Retention magnet system for medical device

ABSTRACT

An external portion of an auditory prosthesis includes an external magnet that interacts with an implantable magnet to hold the external portion against the skin. Magnetic force generated by the stray field of these magnets can disturb the operation of a vibrating element of the auditory prosthesis. The technologies described herein utilize additional magnets disposed within portions of the auditory prosthesis to redirect the magnetic flux, which allows the vibrating element to be disposed more closely to the magnets, reducing the overall height profile of the prosthesis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of U.S. patentapplication Ser. No. 16/376,431, filed Apr. 5, 2019, which claimspriority from U.S. Provisional Application No. 62/763,203, filed Jun. 6,2018, and is also a Continuation-in-part of U.S. Utility patentapplication Ser. No. 15/919,717, filed on Mar. 13, 2018, which claimspriority to PCT/IB2016/001388, filed Sep. 13, 2016, which claimspriority to U.S. Utility patent application Ser. No. 15/158,225, filedMay 18, 2016, now U.S. Pat. No. 9,872,115, which claims priority to U.S.Provisional patent application Ser. No. 62/218,339, filed Sep. 14, 2015,the entire contents of all of these applications being incorporatedherein by reference in their entirety.

BACKGROUND

Hearing loss, which can be due to many different causes, is generally oftwo types: conductive and sensorineural. Sensorineural hearing loss isdue to the absence or destruction of the hair cells in the cochlea thattransduce sound signals into nerve impulses. Various hearing prosthesesare commercially available to provide individuals suffering fromsensorineural hearing loss with the ability to perceive sound. Forexample, cochlear implants use an electrode array implanted in thecochlea of a recipient (i.e., the inner ear of the recipient) to bypassthe mechanisms of the middle and outer ear. More specifically, anelectrical stimulus is provided via the electrode array to the auditorynerve, thereby causing a hearing percept.

Conductive hearing loss occurs when the normal mechanical pathways thatprovide sound to hair cells in the cochlea are impeded, for example, bydamage to the ossicular chain, the ear drum or the ear canal.Individuals suffering from conductive hearing loss can retain some formof residual hearing because some or all of the hair cells in the cochleafunction normally.

Individuals suffering from conductive hearing loss often receive aconventional hearing aid. Such hearing aids rely on principles of airconduction to transmit acoustic signals to the cochlea. In particular, ahearing aid typically uses an arrangement positioned in the recipient'sear canal or on the outer ear to amplify a sound received by the outerear of the recipient. This amplified sound reaches the cochlea causingmotion of the perilymph and stimulation of the auditory nerve.

In contrast to conventional hearing aids, which rely primarily on theprinciples of air conduction, certain types of hearing prosthesescommonly referred to as bone conduction devices, convert a receivedsound into vibrations. The vibrations are transferred through the skullto the cochlea causing motion of the perilymph and stimulation of theauditory nerve, which results in the perception of the received sound.Bone conduction devices are suitable to treat a variety of types ofhearing loss and can be suitable for individuals who cannot derivesufficient benefit from conventional hearing aids.

SUMMARY

An external portion of an auditory prosthesis includes an externalmagnet that interacts with an implantable magnet to hold the externalportion against the skin. The stray magnetic field generated by thesemagnets can disturb the operation of a vibrating element of the auditoryprosthesis. The technologies described herein utilize additional magnetsdisposed within portions of the auditory prosthesis to redirect themagnetic flux, which allows the vibrating element to be disposed moreclosely to the magnets, reducing the overall height profile of theprosthesis. Additionally, this can result in greater magnetic retentionforces, which can allow smaller magnets to be utilized.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A depicts a partial perspective view of a percutaneous boneconduction device worn on a recipient.

FIG. 1B is a schematic diagram of a percutaneous bone conduction device.

FIG. 2 depicts a cross-sectional schematic view of a passivetranscutaneous bone conduction device worn on a recipient.

FIG. 2A depicts a top view of an exemplary embodiment.

FIG. 2B depicts a side view of an exemplary embodiment.

FIG. 2C depicts a side view of an exemplary embodiment.

FIG. 3A depicts a partial cross-sectional schematic view of a passivetranscutaneous bone conduction device worn on a recipient.

FIG. 3B depicts a partial cross-sectional schematic view of a passivetranscutaneous bone conduction device utilizing magnet groups, worn on arecipient.

FIG. 4 is perspective view of a reference magnet group incorporating adeflector.

FIG. 5A is a perspective view of the reference magnet group of FIG. 4without utilizing the deflector.

FIG. 5B is a plot showing retention force for the magnet group with thedeflector of FIG. 4 , as compared to the magnet group without deflectorof FIG. 5A.

FIG. 5C is a plot showing battery force for the magnet group with thedeflector of FIG. 4 , as compared to the magnet group without deflectorof FIG. 5A.

FIG. 6A is a perspective view of a magnet group in accordance with oneexample of the technology.

FIG. 6B is a perspective view of the magnet group of FIG. 6A with analtered battery configuration.

FIG. 6C is a plot showing retention force for the magnet group with thedeflector of FIG. 4 , as compared to the magnet groups of FIGS. 6A and6B.

FIG. 6D is a plot showing battery force for the magnet group with thedeflector of FIG. 4 , as compared to the magnet groups of FIGS. 6A and6B.

FIG. 6E to FIG. 6M variously depict exemplary magnet apparatuses.

FIG. 6N to FIG. 6S variously depict additional exemplary magnetapparatuses.

FIGS. 6T1 to 6T3 depict cross-sections of exemplary apparatuses.

FIGS. 6U to 6W2 depict exemplary implantable components.

FIG. 6X presents an exemplary magnet arrangement.

FIG. 6Y presents a chart of data.

FIG. 7A is a perspective view of a magnet group in accordance withanother example of the technology.

FIG. 7B is a plot showing retention force versus magnet separation forthe magnet group of FIG. 7A.

FIG. 7C is a plot showing battery force versus magnet separation for themagnet group of FIG. 7A.

FIG. 8A is a perspective view of a magnet group in accordance withanother example of the technology.

FIG. 8B is a plot showing retention force versus magnet separation forthe magnet group of FIG. 8A.

FIG. 8C is a plot showing battery force versus magnet separation for themagnet group of FIG. 8A.

FIG. 9A is a perspective view of a magnet group in accordance withanother example of the technology.

FIG. 9B is a plot showing retention force versus magnet separation forthe magnet group of FIG. 9A.

FIG. 9C is a plot showing battery force versus magnet separation for themagnet group of FIG. 9A.

FIG. 10A is a perspective view of a magnet group in accordance withanother example of the technology.

FIG. 10B is a plot showing retention force versus magnet separation forthe magnet group of FIG. 10A.

FIG. 10C is a plot showing battery force versus magnet separation forthe magnet group of FIG. 10A.

FIG. 11A is a perspective view of a magnet group in accordance withanother example of the technology.

FIG. 11B is a plot showing retention force versus magnet separation forthe magnet group of FIG. 11A.

FIG. 11C is a plot showing battery force versus magnet separation forthe magnet group of FIG. 11A.

FIGS. 12-19 present exemplary flowcharts for exemplary methods.

FIGS. 20A to 27 present cross-sections (partial and/or full) of someexemplary magnet apparatuses.

FIG. 28 presents an isometric view of an exemplary embodiment.

FIGS. 29-32 present some graphics associated with some exemplaryembodiments.

FIGS. 33 to 37 present cross-sections (partial and/or full) of someexemplary magnet apparatuses.

FIG. 38 presents a top view of an exemplary embodiment.

FIG. 39 presents a side view of an exemplary embodiment.

FIGS. 40 to 44 present cross-sections (partial and/or full) of someexemplary magnet apparatuses.

FIGS. 45 and 46 present isometric views of exemplary embodiments.

FIGS. 47-51 present top views of some exemplary embodiments.

FIG. 52 presents an isometric view of an exemplary embodiment.

FIGS. 53-55 present cross-sections of some exemplary embodiments.

DETAILED DESCRIPTION

The technologies described herein can be utilized in auditory prosthesessuch as passive transcutaneous bone conduction devices, activetranscutaneous bone conduction devices, cochlear implants, or directacoustic stimulators. There are typically one or two magnets disposed inan external portion and/or implantable portion of the auditoryprosthesis. The magnetic field of the external magnet(s) interacts witha magnetic field of the magnet(s) disposed in an implantable portion ofthe prosthesis. Other types of auditory prostheses, such as middle earprostheses, and direct acoustic stimulators utilize a similarconfiguration where an external magnet mates with an implantable magnetto hold the external portion to the skin. In another example, apercutaneous bone conduction prosthesis utilizes an anchor thatpenetrates the skin of the head. An external portion of the auditoryprosthesis is secured to the anchor with a snap connection. By utilizingthe technologies described herein, the anchor can be manufactured inwhole or in part of a magnetic material, and a mating magnet group canbe disposed in the external portion to mate with the anchor, eitheralone, or also in conjunction with a snap connection. Moreover, thetechnologies disclosed herein can be utilized with any type ofmulti-component medical device where one portion of the device isimplanted in a recipient, and the other portion is secured to the skinof a patient via a force generated by a magnetic field. For clarity,however, the technologies will be described generally in the context ofauditory prostheses that are bone conduction devices, and morespecifically transcutaneous bone conduction devices.

Additionally, many of the magnet groups depicted herein are depicted assubstantially arc-shaped. Arc-shaped magnets are depicted and describedherein so as to enable valid comparisons between magnet groups havingdifferent configurations. Regardless, the magnets can be of virtuallyany form factor or shape, as required or desired for a particularapplication. Contemplated shapes include rectangular, crescent,triangular, trapezoidal, circle segments, and so on. Additionally,substantially plate-like or flat magnets are disclosed in severalembodiments, but magnets having variable thicknesses are alsocontemplated. Additionally, the magnet groups can be in the form on asingle element that has multiple polarities. Different examples ofexternal and implantable magnet groups, as well as performancecharacteristics thereof, are described in more detail below. The magnetsdescribed in the examples herein have shape that can be defined assimilar to at least part of a disk (e.g., in whole or in part, having around outer perimeter with generally flat upper and lower surfaces). Ingeneral, for such disk-like magnets, an axially magnetized magnet hasone pole on one of the flat surfaces and a second pole disposed on theopposite flat surface. For such disk-like magnets, a diametricallymagnetized magnet has one pole on one hemisphere of the disk, and asecond pole disposed on the other hemisphere of the disk. A person ofskill in the art would recognize other magnet configurations that wouldfall within the scope of the described technology.

FIG. 1A depicts a partial perspective view of a percutaneous boneconduction device 100 positioned behind outer ear 101 of the recipientand includes a sound input element 126 to receive sound signals 107. Thesound input element 126 can be a microphone, telecoil, or similar. Inthe present example, sound input element 126 can be located, forexample, on or in bone conduction device 100, or on a cable extendingfrom bone conduction device 100. Also, bone conduction device 100includes a sound processor (not shown), a vibrating electromagneticactuator and/or various other operational components.

More particularly, sound input device 126 converts received soundsignals into electrical signals. These electrical signals are processedby the sound processor. The sound processor generates control signalsthat cause the actuator to vibrate. In other words, the actuatorconverts the electrical signals into mechanical force to impartvibrations to skull bone 136 of the recipient.

Bone conduction device 100 further includes coupling apparatus 140 toattach bone conduction device 100 to the recipient. In the example ofFIG. 1A, coupling apparatus 140 is attached to an anchor system (notshown) implanted in the recipient. An exemplary anchor system (alsoreferred to as a fixation system) can include a percutaneous abutmentfixed to the recipient's skull bone 136. The abutment extends from skullbone 136 through muscle 134, fat 128, and skin 132 so that couplingapparatus 140 can be attached thereto. Such a percutaneous abutmentprovides an attachment location for coupling apparatus 140 thatfacilitates efficient transmission of mechanical force.

It is noted that sound input element 126 can include devices other thana microphone, such as, for example, a telecoil, etc. In an exemplaryembodiment, sound input element 126 can be located remote in a BTEdevice (not shown) supported by the ear and in communication with thebone conduction device 100 via a cable. Alternatively, sound inputelement 126 can be subcutaneously implanted in the recipient, orpositioned in the recipient's ear canal or positioned within the pinna.Sound input element 126 can also be a component that receives anelectronic signal indicative of sound, such as, from an external audiodevice. For example, sound input element 126 can receive a sound signalin the form of an electrical signal from an MP3 player or a smartphoneelectronically connected to sound input element 126.

The sound processing unit of the auditory prosthesis processes theoutput of the sound input element 126, which is typically in the form ofan electrical signal. The processing unit generates control signals thatcause an associated actuator to vibrate. These mechanical vibrations aredelivered by an external portion of the auditory prosthesis 100, asdescribed below.

FIG. 1B is a schematic diagram of a percutaneous bone conduction device100. Sound 107 is received by sound input element 152. In somearrangements, sound input element 152 is a microphone configured toreceive sound 107, and to convert sound 107 into electrical signal 154.Alternatively, sound 107 is received by sound input element 152 as anelectrical signal. As shown in FIG. 1B, electrical signal 154 is outputby sound input element 152 to electronics module 156. Electronics module156 is configured to convert electrical signal 154 into adjustedelectrical signal 158. As described below in more detail, electronicsmodule 156 can include a sound processor, control electronics,transducer drive components, and a variety of other elements.

As shown in FIG. 1B, transducer 160 receives adjusted electrical signal158 and generates a mechanical output force in the form of vibrationsthat is delivered to the skull of the recipient via anchor system 162,which is coupled to bone conduction device 100. Delivery of this outputforce causes motion or vibration of the recipient's skull, therebyactivating the hair cells in the recipient's cochlea (not shown) viacochlea fluid motion.

FIG. 1B also illustrates power module 170. Power module 170 provideselectrical power to one or more components of bone conduction device100. For ease of illustration, power module 170 has been shown connectedonly to user interface module 168 and electronics module 156. However,it should be appreciated that power module 170 can be used to supplypower to any electrically powered circuits/components of bone conductiondevice 100.

User interface module 168, which is included in bone conduction device100, allows the recipient to interact with bone conduction device 100.For example, user interface module 168 can allow the recipient to adjustthe volume, alter the speech processing strategies, power on/off thedevice, etc. In the example of FIG. 1B, user interface module 168communicates with electronics module 156 via signal line 164.

Bone conduction device 100 can further include an external interfacemodule 166 that can be used to connect electronics module 156 to anexternal device, such as a fitting system. Using external interfacemodule 166, the external device, can obtain information from the boneconduction device 100 (e.g., the current parameters, data, alarms, etc.)and/or modify the parameters of the bone conduction device 100 used inprocessing received sounds and/or performing other functions.

In the example of FIG. 1B, sound input element 152, electronics module156, transducer 160, power module 170, user interface module 168, andexternal interface module have been shown as integrated in a singlehousing, referred to as an auditory prosthesis housing or an externalportion housing 150. However, it should be appreciated that in certainexamples, one or more of the illustrated components can be housed inseparate or different housings. Similarly, it should also be appreciatedthat in such embodiments, direct connections between the various modulesand devices are not necessary and that the components can communicate,for example, via wireless connections.

FIG. 2 depicts an example of a transcutaneous bone conduction device 200that includes an external portion 204 and an implantable portion 206.The transcutaneous bone conduction device 200 of FIG. 2 is a passivetranscutaneous bone conduction device in that a vibrating actuator 208is located in the external portion 204. Vibrating actuator 208 islocated in housing 210 of the external component, and is coupled toplate 212. Plate 212 can be in the form of a permanent magnet, a groupof magnets, and/or in another form that generates and/or is reactive toa magnetic field, or otherwise permits the establishment of magneticattraction between the external portion 204 and the implantable portion206 sufficient to hold the external portion 204 against the skin of therecipient. Magnetic attraction can be further enhanced by utilization ofa magnetic implantable plate 216. A single external magnet 212 of afirst polarity and a single implantable magnet 216 of a second polarity,are depicted in FIG. 2 . In alternative embodiments, two magnets in boththe external portion 204 and implantable portion 206 can be utilized. Ina further alternative embodiment, the plate 212 can include anadditional plastic or biocompatible housing (not shown) thatencapsulates plate 212 and contacts the skin of the recipient.

The vibrating actuator 208 is a device that converts electrical signalsinto vibration. In operation, sound input element 126 converts soundinto electrical signals. Specifically, the transcutaneous boneconduction device 200 provides these electrical signals to vibratingactuator 208, or to a sound processor (not shown) that processes theelectrical signals, and then provides those processed signals tovibrating actuator 208. The vibrating actuator 208 converts theelectrical signals into vibrations. Because vibrating actuator 208 ismechanically coupled to plate 212, the vibrations are transferred fromthe vibrating actuator 208 to plate 212. Implantable plate assembly 214is part of the implantable portion 206, and is made of a ferromagneticmaterial that can be in the form of a permanent magnet, that generatesand/or is reactive to a magnetic field, or otherwise permits theestablishment of a magnetic attraction between the external portion 204and the implantable portion 206 sufficient to hold the external portion204 against the skin 132 of the recipient. Additional details regardingthe magnet groups that can be utilized in both the external portion 204and the implantable portion 206 are described in more detail herein.Accordingly, vibrations produced by the vibrating actuator 208 of theexternal portion 204 are transferred from plate 212 across the skin 132to implantable plate 216 of implantable plate assembly 214. This can beaccomplished as a result of mechanical conduction of the vibrationsthrough the skin 132, resulting from the external portion 204 being indirect contact with the skin 132 and/or from the magnetic field betweenthe two plates 212, 216. These vibrations are transferred without acomponent penetrating the skin 132, fat 128, or muscular 134 layers onthe head.

As can be seen, the implantable plate assembly 214 is substantiallyrigidly attached to bone fixture 220 in this embodiment. Implantableplate assembly 214 includes through hole 220 that is contoured to theouter contours of the bone fixture 218, in this case, a bone screw thatis secured to the bone 136 of the skull. This through hole 220 thusforms a bone fixture interface section that is contoured to the exposedsection of the bone fixture 218. In an exemplary embodiment, thesections are sized and dimensioned such that at least a slip fit or aninterference fit exists with respect to the sections. Plate screw 222 isused to secure implantable plate assembly 214 to bone fixture 218. Ascan be seen in FIG. 2 , the head of the plate screw 222 is larger thanthe hole through the implantable plate assembly 214, and thus the platescrew 222 positively retains the implantable plate assembly 214 to thebone fixture 218. In certain embodiments, a silicon layer 224 is locatedbetween the implantable plate 216 and bone 136 of the skull.

FIG. 2A depicts an exemplary high-level diagram of another exemplaryprosthesis including an implantable component 300 of a so-calledcochlear implant system, which can be a totally implantable system or asystem with an external component (sound processor, RF antenna,microphone, etc.—more on this below) and the implantable component 300,looking downward from outside the skull towards the skull. As can beseen, implantable component 300 includes a magnet 160 that is surroundedby a coil 137 that is in two-way communication (although in someinstances, the communication is one-way) with a stimulator unit 122,which in turn is in communication with the electrode assembly 118. Thisis basically a classic implantable component of a so-called cochlearimplant.

Still with reference to FIG. 2A, it is noted that the stimulator unit122, and the magnet apparatus 160 are located in a body made of anelastomeric material 199, such as by way of example only and not by wayof limitation, silicone. Hereinafter, the elastomeric material 199 ofthe body will be often referred to as silicone. However, it is notedthat any reference to silicone herein also corresponds to a reference toany other type of component that will enable the teachings detailedherein and/or variations thereof, such as, by way of example and not byway of limitation only, bio-compatible rubber, etc.

As can be seen in FIG. 2A, the housing made of elastomeric material 199includes a slit 180 (not shown in FIG. 2B, as, in some instances, theslit is not utilized, and in other instances, the slit is locatedelsewhere—more on this below). In some variations, the slit 180 hasutilitarian value in that it can enable insertion and/or removal of themagnet apparatus 160 from the body made of elastomeric material 199,such as for MRI treatment. Magnet apparatus is surrounded by silicone170 of the silicone body 199, and the silicone holds the magnetapparatus in place, and also supports the coil.

It is noted that magnet apparatus 160 is presented in a conceptualmanner. In this regard, it is noted that in at least some instances, themagnet apparatus 160 is an assembly that includes a magnet surrounded bya biocompatible coating. Still further by way of example, magnetapparatus 160 is an assembly where the magnet is located within acontainer having interior dimensions generally corresponding to theexterior dimensions of the magnet, although in other embodiments, thisis not the case. This container can be hermetically sealed, thusisolating the magnet in the container from body fluids of the recipientthat penetrate the housing (the same principle of operation occurs withrespect to the aforementioned coated magnet). In an exemplaryembodiment, this container permits the magnet to revolve or otherwisemove relative to the container, as is known in the art. Additionaldetails of the container will be described below. In this regard, it isnoted that while sometimes the term magnet is used as shorthand for thephrase magnet apparatus, and thus any disclosure herein with respect toa magnet also corresponds to a disclosure of a magnet apparatusaccording to the aforementioned embodiments and/or variations thereofand/or any other configuration that can have utilitarian value accordingto the teachings detailed herein.

With reference now to FIG. 2B it is noted that the outlines of thesilicone body made from elastomeric material 199 are presented in dashedline format for ease of discussion. In an exemplary embodiment, siliconeor some other elastomeric material fills the interior within the dashedline, other than the other components of the implantable device (e.g.,plates, magnet, stimulator, etc.). That said, in an alternativeembodiment, silicone or some other elastomeric material substantiallyfills the interior within the dashed lines other than the components ofthe implantable device (e.g., there can be pockets within the dashedline in which no components and no silicone are located).

It is noted that FIGS. 2A and 2B are conceptual figures presented forpurposes of discussion. Commercial embodiments corresponding to theseFIGs. can be different from that depicted in the figures.

FIG. 2C depicts an exemplary embodiment of a transcutaneous boneconduction device 499 according to another embodiment that includes anexternal device 440 and an implantable component 450. The transcutaneousbone conduction device 499 of FIG. 2C is an active transcutaneous boneconduction device in that the vibrating actuator 452 (which can be anelectromagnetic actuator, or a piezoelectric actuator, etc.) is locatedin the implantable component 450. Specifically, a vibratory element inthe form of vibrating actuator 452 is located in housing 454 of theimplantable component 450. In an exemplary embodiment, much like thevibrating actuator 342 described above with respect to transcutaneousbone conduction device 300, the vibrating actuator 452 is a device thatconverts electrical signals into vibration.

External component 440 includes a sound input element 126 that convertssound into electrical signals. Specifically, the transcutaneous boneconduction device 499 provides these electrical signals to vibratingactuator 452, or to a sound processor (not shown) that processes theelectrical signals, and then provides those processed signals to theimplantable component 450 through the skin of the recipient via amagnetic inductance link. In this regard, a transmitter coil 442 of theexternal component 440 transmits these signals to implanted receivercoil 456 located in housing 458 of the implantable component 450.Components (not shown) in the housing 458, such as, for example, asignal generator or an implanted sound processor, then generateelectrical signals to be delivered to vibrating actuator 452 viaelectrical lead assembly 460. The vibrating actuator 452 converts theelectrical signals into vibrations.

The vibrating actuator 452 is mechanically coupled to the housing 454.Housing 454 and vibrating actuator 452 collectively form a vibratoryapparatus 453. The housing 454 is substantially rigidly attached to bonefixture 341.

As with the embodiments above, the external device 440 is held againstthe skin via magnetic attraction between a ferromagnetic body in theexternal device 440 and the implantable component 450, such as in theimplanted receiver coil apparatus 456.

The teachings detailed herein can be used in any of the embodimentsdisclosed above and/or in other medical devices.

FIG. 3A depicts a partial cross-sectional schematic view of a passivetranscutaneous bone conduction device 300 a for a recipient R. Only skin132 of the recipient R is depicted for clarity. The bone conductiondevice 300 a includes an external portion 302 and an implantable portion304. For clarity, only certain components of each of the externalportion 302 and the implantable portion 304 are depicted. Each of theexternal portion 302 and the implantable portion 304 include reciprocalgroups of magnets that form a transcutaneous coupling between thoseportions 302, 304, via a closed magnetic circuit. Other components inthe external portion 302 and the implantable portion 304, e.g.,housings, sound processing components, batteries, microphones,actuators, anchors, etc., are described above, but not depicted in FIG.3A. The external portion 302 includes a plurality of external magnets308, 310. In this embodiment, magnet 308 has a magnetization direction(e.g., as defined by the north and south poles thereof) that extendsinto the skin 132 of the recipient R, while magnet 310 has amagnetization direction that extends away from the skin 132. As such,these magnetization directions are substantially parallel and opposed toeach other. In the illustrated example, the implantable portion 304 alsoincludes two magnets 314, 316. Magnet 314 has a magnetization directionthat is both substantially parallel to and harmonized with themagnetization direction of magnet 308, while magnet 316 has amagnetization direction that is both substantially parallel to andharmonized with the magnetization direction of magnet 310. The magnets314, 316 can be disposed in a housing.

Magnetic flux generated by the magnets 308, 310, 314, 316 is alsodepicted in FIG. 3A. The magnetic field, and especially stray portionsthereof, can interfere with the operation of the sound processor orother components disposed in the external portion 302. Stray portionsare generally not depicted in FIG. 3A. Forces and/or torques aregenerated on components disposed in the external portion 302, which cancompromise the functionality of the actuator, by affecting thefunctionality of the actuator suspension, thus leading to worsenedfeedback performance of the device 300. The performance of the vibratingactuator (if electromagnetic) can also be worsened by stray magneticfields penetrating the actuator, thus reducing sensitivity and causingdistortion.

FIG. 3B depicts a partial cross-sectional schematic view of a passivetranscutaneous bone conduction device 300 b for a recipient R. Thisdevice 300 b utilizes additional magnets 312, 318 to reduce straymagnetic fields and otherwise improve performance. Utilization ofmagnets 312 and 318 can reduce interferences and further improvefunctionality of the auditory prosthesis 300 b. The magnetizationdirection of magnet 312 is substantially parallel and opposed tomagnetization direction of magnet 318. Both of these magnetizationdirections are substantially parallel to the skin 132. The magneticcomponents 312, 318 divert the magnetic flux as depicted in FIG. 3B, toreduce the stray magnetic fields, thus correcting or minimizing theabove-identified and other problems. Regardless of the number of magnetsused, arranging the magnets 312, 318 such that the magnetizationdirections are in a circuit that defines a substantially continuousmagnetic flux path in the medical device. In other words, the magnets312, 318 create a shortcut for flux on that side of the medical device.As such, each of magnets 308, 310, 312, 314, 316, and 318 define alocalized section of the flux path. By creating the circuit ofmagnetization direction, the magnetic flux is distributed asymmetricallyon opposing sides of the medical device. This asymmetrical distribution,in practical terms, results in the retention force on one side of themagnets (e.g., 308 and 310) being increased and the magneticinterference on the other being reduced. Retention force is increasedbecause the depicted arrangement of the magnets produces a fluxconcentration proximate the skin 132. In the depicted example, magneticretention force proximate the skin 132 is increased, while magneticinterference away from the skin (e.g., where the sound processor,vibrating actuator, and other components are located) is decreased.

Each magnet in each magnet group generates its own magnetic field.Together, magnets 308, 310, 312, 314, 316, and 318 form a magnet group(and generate a group magnetic field), although subsets of these magnets(e.g., magnets 308, 310, 312 in the external portion 302; and magnets314, 316, 318 in the implantable portion 304) can also form magnetgroups (and their own group magnetic fields). Moreover, the magnets ineach magnet group need not be physically separate components, but can bea unitary part having different magnetization directions, which can beaccomplished by the magnetization process. The effect on the magneticfield is depicted in FIG. 3B, where the field is channeled through themagnet 312, so as to reduce stray magnetic flux. Of course, magnet 318channels the field so the stray flux generated by the implantablemagnets 314, 316 is also reduced.

Magnets having differing form factors and magnetization directions arecontemplated. For example, magnets that are diametrically magnetized andmagnets that are axially magnetized are contemplated for applicationssuch as bone conduction devices, to maintain a low profile of theauditory prosthesis. In the depicted embodiment, magnets 308, 310, 314,and 316 are axially magnetized so as to have a magnetization directionnormal to a transcutaneous interface (i.e., the interface between theexternal portion 302 and the implantable portion 304). The magnets 312,318 are magnetized through the width so as to have a magnetizationdirection transverse to the magnetization direction of magnets 308, 310,314, and 316. In examples where a unitary magnet is used, the unitarymagnet can be magnetized such that portions thereof are diametricallymagnetized, while other portions thereof are axially magnetized.Moreover, each magnet of a given magnet group can physically contactmagnets proximate thereto so as to form a continuous flux path withinthe medical device (or the implanted component), if desired. Otherconfigurations are contemplated and described in more detail below.

FIG. 4 is perspective view of a reference magnet group 400 incorporatinga deflector 402. This configuration of the reference magnet group 400can be utilized in a transcutaneous bone conduction device having bothexternal and implantable portions. In that regard, external magnet group404 includes two magnets 404 a, 404 b that would be disposed in ahousing of an external portion. Implantable magnet group 406 includestwo magnets 406 c, 406 d that would be disposed in a housing of animplantable portion. In this and other examples of magnet groupsdepicted herein, the housings and other components of the auditoryprosthesis are not depicted for clarity. A battery 408 is generallyabove the external magnets 404 a, 404 b where it is typically located inan auditory prosthesis. The location and orientation of the battery,relative to various magnet groups as described herein is also discussedfurther below. The deflector 402 in this case, is a soft magneticcomponent such as soft iron or Permalloy, which is utilized to channelmagnetic flux between the two external magnets 404 a, 404 b. Utilizationof a deflector 402 also helps reduce the stray magnetic flux which cancause interference to components. In the depicted embodiment, thedeflector 402 bridges a gap 410 between the external magnets 404 a, 404b. Ribs 412 can extend from the deflector 402 so as to extend into thegap 410 therebetween.

In this and subsequent figures, magnetization directions are depicted assingle arrows for clarity. Magnetization direction is an indication ofthe direction of the magnetic field which is, of course, not limited toa single vector extending from a discrete point on a magnet, but insteadextends generally through the body of a magnet, dispersed along theentire area thereof. Here, the magnetization directions M_(A), M_(C) ofmagnets 404 a, 406 c are substantially aligned with each other,indicating that the north poles N of both magnets 404 a, 406 c aredisposed proximate upper portions thereof, while the south poles S aredisposed proximate lower portions thereof. As such, the magnetizationdirections M_(A) M_(C) of magnets 404 a, 406 c can be described assubstantially parallel and harmonized with each other. Similarly, themagnetization directions M_(B), M_(D) of magnets 404 b, 406 d aresubstantially aligned with each other, indicating that the north poles Nof both magnets 404 b, 406 d are disposed proximate lower portionsthereof, while the south poles S are disposed proximate upper portionsthereof. As such, the magnetization directions M_(B), M_(D) of magnets404 b, 406 d can be described as substantially parallel and harmonizedwith each other. The magnetization directions M_(A), M_(C), and M_(B),M_(D), however, can be characterized as being substantially parallel andopposed.

The configuration and performance characteristics of the magnet group400 depicted herein, is a reference against which to compare thecharacteristics of other magnet groups depicted herein and those notnecessarily described, but consistent with the disclosures herein. Theseperformance characteristics include retention force, which is anindication of the mutual attraction force between external andimplantable magnets, and battery force, which is an indication of theforce exerted on the metal casing of a battery by the magnets. Too weakof a retention force can cause the external portion to fall offundesirably, while too strong of a retention force can cause discomfortor skin necrosis. With regard to battery force, a low battery force isdescribed since high loads will preload a suspension spring upon whichthe battery and sound processor are mounted. This makes for a lesseffective vibration isolator. Other performance characteristics, such asinterference of the stray field with electronic components in the soundprocessor, can also be improved with utilization of magnet groups suchas those described herein, but are not necessarily discussed in detail.

FIG. 5A is a perspective view of the reference magnet group 400 of FIG.4 , but without the presence of the deflector 402. The heights of magnet504 a and 504 b are the same as the overall heights of magnets 404 a or404 b and deflector plate 402 (depicted in FIG. 4 ). Thus, whencomparing different magnet configurations, this is done for the samecharacteristic dimensions of height and diameter. In that case, themagnet group of FIG. 5A is depicted as magnet group 500 and not allelements thereof are necessarily described further. Moreover, thecomponents are generally numbered consistently with the components ofFIG. 4 , beginning with 500. FIG. 5B is a plot showing retention forcefor the magnet group 400 (with the deflector 402) of FIG. 4 , ascompared to the magnet group 500 of FIG. 5A (without a deflector). Onthe horizontal scale, the distance between an external magnet group(e.g., magnet group 404) and an implantable magnet group (e.g., magnetgroup 406) is depicted. This distance can vary from recipient torecipient based on the thickness of the skin flap on the head,implantation depth, etc. As can be seen, the retention force of magnetgroup 400 is comparable to that of magnet group 500, across a range ofseparation distances. As such, it can be confirmed that the deflector402 has little effect on retention force. FIG. 5C is a plot showingbattery force for the magnet group 400 (with the deflector 402) of FIG.4 , as compared to the magnet group 500 of FIG. 5A (without adeflector). Across a range of separation distances between the externalmagnet group and implantable magnet group, however, the difference inbattery force is marked, which indicates that utilization of a deflectorhas a significant effect on battery force. In case of a magnet groupwithout deflector, there is a significant preload on a suspensionspring.

FIG. 6A is a perspective view of a magnet group 600 in accordance withone example of the technology. Many of the components are generallynumbered consistently with the components of FIG. 4 , beginning with600, and not all elements thereof are necessarily described further.External magnet group includes magnets 604 a and 604 b, each having anarced form factor with two straight ends or edges. External magnet group604 also includes a third magnet 604 e, disposed between the ends ofmagnets 604 a and 604 b. In the depicted example, the third magnet 604 eis in two parts, and, in that regard, can be considered to be twodiscrete magnets, disposed between different ends of magnets 604 a and604 b. In other examples, magnet 604 e can be configured as a singlepart, typically defining a gap 610 therein for receipt of a fixationscrew 222 (as depicted in FIG. 2 ). Magnetization direction M_(E) isdepicted, again, in a simplified form as a single vector substantiallyorthogonal to magnetization directions M_(A), M_(B). This magnetizationdirection M_(E) indicates that the north pole N of magnet 604 e isdisposed proximate magnet 604 b, while the south pole S is disposedproximate magnet 604 a. By orienting the poles as such, magnetic flux ofthe first magnet 604 a is diverted more directly to the second magnet604 b, via the third magnet 604 e. Similarly, magnet group 606 alsoincludes a third magnet 606 f, disposed between magnets 606 c and 606 d.In the depicted example, magnet 606 f is in two parts, but in otherexamples, magnet 606 f can be configured as a single part. Magnetizationdirection M_(F) is depicted, again, in a simplified form as a singlevector substantially orthogonal to magnetization directions M_(C),M_(D). This magnetization direction M_(F) indicates that the north poleN of magnet 606 f is disposed proximate magnet 606 c, while the southpole S is disposed proximate magnet 606 d. By orienting the poles assuch, magnetic flux of the first magnet 606 d is diverted more directlyto the second magnet 606 c, via the third magnet 606 f. It should benoted that the magnetization directions M_(E) and M_(F) are bothsubstantially parallel and opposed to each other.

FIG. 6B is a perspective view of the magnet group 600′ of FIG. 6A with adifferent battery 608 configuration. The components are generallynumbered consistently with the components of FIG. 6A, and not allelements thereof are necessarily described further. Notably, therelative position of the battery 608 and magnet group 600′ has changed,although the absolute separation between the battery 608 and the magnetgroup (determined from the axis of rotational symmetry A_(R)) remainsthe same. The battery 608 shown in FIG. 6B is disposed adjacent thethird magnet 604 e. This battery position is beneficial to achieve a lowbattery force.

The magnets 604 a, 604 b, 604 e of the external magnet group aredisposed in a circuit that defines a substantially continuous flux paththrough the external component. Magnetic flux is channeled along theflux path following the magnetization direction of the respectivemagnets: from the first end magnet 604 a, through the intermediate thirdmagnet 604 e, to the second end magnet 604 b. This reduces the incidenceof stray magnetic flux adjacent the intermediate magnet 604 e where thebattery 608 is positioned in FIG. 6B.

FIG. 6C is a plot showing retention force for the magnet group 400 withthe deflector of FIG. 4 , as compared to the magnet groups 600, 600′ ofFIGS. 6A and 6B, respectively. From this graph, the increase on magnetretention force resulting from the use of additional magnets (e.g.,magnets 604 e, 606 f) is clear, regardless of the orientation of thebattery. As such, this increase in retention force can allowcomparatively smaller magnets to be used which can reduce the overallsize of the external and implantable portion of the auditory prosthesis.FIG. 6D is a plot showing battery force for the magnet group 400 (withthe deflector) of FIG. 4 , as compared to the magnet groups 600, 600′ ofFIGS. 6A and 6B, respectively. Noticeably here, battery force of themagnet group 600′ of FIG. 6B is consistent with that of the referencemagnet group 400 of FIG. 4 , while the battery force of magnet group 600of FIG. 6A differs significantly. This indicates that the configurationof magnet group 600 (and the associated battery) is less desirable.

In view of the above, it can be seen that in an exemplary embodimentthere is an apparatus, such as an implantable component of a medicaldevice, such as a hearing prosthesis, or any other device, or anexternal component of a medical device, for that matter, comprising ahousing and a magnet group disposed in the housing. In an exemplaryembodiment, the magnet group includes a first magnet portion thatgenerates a first magnetic field, such as by way of example only and notby way of limitation, 606 d, a second magnetic portion that generates asecond magnetic field, such as by way of example only and not by way oflimitation, 606 c, and a third magnetic portion that generates a thirdmagnetic field, such as by way of example only and not by way oflimitation, 606 f. In an exemplary embodiment, each of the first magnetthe second magnet are arranged so as to reduce a stray magnetic field ofthe magnet group. The first magnetic field, the second magnetic field,and the third magnetic field define the group magnetic field.

In an exemplary embodiment of the embodiment just described, the firstmagnet portion and second magnet portion are axially magnetized, and thethird magnet portion is diametrically magnetized. Consistent with theteachings detailed herein, in an exemplary embodiment, the third magnetportion is disposed so as to divert a magnetic flux of the first magnetportion to the second magnet portion.

Further, consistent with the teachings detailed herein, in an exemplaryembodiment, the aforementioned first magnet portion is a first endmagnet with a magnetization direction that extends normal to atranscutaneous interface of the apparatus and the second magnet portionis a second end magnet with a magnetization direction extending parallelto the magnetization direction of the first end magnet in an oppositedirection. In this embodiment the third magnet portion is anintermediate magnet that is disposed between the first and second endmagnets, the intermediate magnet having a magnetization direction thatis transverse to magnetization direction of the first and second endmagnets.

FIG. 6A presents to separate elements 606 f that are separated by aspace. In an exemplary embodiment, the two separate elements areconnected to one another by the magnet portions 606 d and 606 c,consistent with the embodiment of FIG. 6A. In an exemplary embodiment,adhesive or the like is utilized between the interfacing surfaces of themagnet portions 606 d and 606 c, and the respective correspondingportions of 606 f FIG. 6E presents an exemplary location where adhesive620 can be located at the facing surfaces of the respective magnetportions. FIG. 6F depicts another exemplary embodiment that utilizesplates 625 to hold the magnet elements 606 f to the magnet portions 606c and 606 d. In an exemplary embodiment, these can be plastic plateswhile in other embodiments these can be metallic plates. In an exemplaryembodiment, the plates are bolted or screwed to the respective magnetsutilizing bolts/screws 626, while in other embodiments, adhesive isutilized to glue the plates to the magnets. In an exemplary embodiment,there can be plates 625 located on the opposite sides (not shown). Thebolts can extend all the way through to the opposite side platesconnecting everything together. Any arrangement that can secure theplates to the magnet elements can be utilized in at least some exemplaryembodiments.

In an exemplary embodiment, the magnet group is configured such that thefirst magnetic portion, the second magnetic portion and the thirdmagnetic portion establish a device such that the first portion and thethird portion are contiguous, and the second portion and the thirdportion are contiguous. In an exemplary embodiment, a cross-section ofthe magnet group lying on a plane perpendicular to a longitudinal axisof the magnet group contains only the gap for the hole 621, while, withrespect to other embodiments that will be described below, there are nogaps. In some embodiments, the magnet group is configured such that thefirst magnetic portion, the second magnetic portion and the thirdmagnetic portion are portions that are solid portions In an exemplaryembodiment, the magnet group is configured such that the first magneticportion, the second magnetic portion and the third magnetic portion areportions that have solid cross-sections when taken on a planeperpendicular to a longitudinal axis of the magnet group, and the secondmagnetic field extends normal to the first and third magnetic fields,and the second magnetic portion extends from one side of the group to anopposite side of the group.

In an exemplary embodiment, there are only the three portions that makeup the magnet group. In an exemplary embodiment, there are only 2, 3, 4,5, or 6 portions that make up the magnet group.

Other types of arrangements can be utilized to hold the elements 606 ftogether without the utilization of the magnet portions 606 d and 606 c.FIG. 6F shows an example of the utilization of non-metallic braces 630that extend between the two magnet portions 606 f and also extend intothe two magnet portion 606 f, whereas in other exemplary embodiments,the braces are adhesively glued or otherwise adhered (welded, soldered,etc.) to the surfaces of the magnet portions 606 f Here, the braces 630are in the form of plastic rods that extend from cylindrical holesdrilled into the inner side walls of the magnet portions 606 f The rodsare interference fitted into the holes, while in other embodiments, andadhesive can be utilized to hold them into the holes. Again, as notedabove, instead, the rods could be glued against the surfaces of theinner walls facing each other with respect to the element 606 f.

While the embodiment seen in FIG. 6G shows two separate braces 630, insome other embodiments, 1 or 3 or 4 or 5 or 6 or more braces could beutilized to all the magnets together. Any number of braces can beutilized in at least some exemplary embodiments. While the embodimentsdepicted round rods being utilized, and other embodiments, rectangularcross-sections beams can be utilized. Any configuration of braces thatcan be utilized to implement the teachings detailed herein can beutilized at least some exemplary embodiments.

FIG. 6H presents yet another exemplary embodiment of a structure 640that connects the two separate elements of 606 f together. Here, element640 can be a plate with curved ends that correspond to the curvature ofthe faces of elements 606 f. In an exemplary embodiment, the height ofplate 640 can correspond to that of the elements 606 f, while in otherembodiments, the height can be less than or greater than such. This isalso the case with respect to at least some of the embodiments of thebraces 630 presented above.

In the embodiments of FIGS. 6H, 6G, and 6F the structure that holds thetwo elements together is not in contact with the elements 606 d and/or606 c. That said, FIG. 6I presents an alternate embodiment where thestructure is also in contact with the elements 606 d and 606 c. In thisexemplary embodiment, structure 645 fills the whole between the magnetelements. In an exemplary embodiment, structure 640 and 645 can be gluedto the respective magnet elements to hold the magnets in place. In anexemplary embodiment, only elements 606 f are glued to the structure645, while in other embodiments, all of the magnet elements are so gluedto the structure 645.

Consistent with the teachings detailed herein, in an exemplaryembodiment, the structure that is utilized to hold the magnet elements606 f together can include a space that permits the screw, such as screw222, to pass through from one side to the other, consistent with theteachings detailed herein vis-a-vis the space between the two separateelements 606 f. In an exemplary embodiment, the spaces between beams 640is such that the screw can pass therethrough. In an exemplaryembodiment, distance D1 is less than, equal to and/or greater than 0.5,1.0, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9,9.5, 10, 11, 12, 13, or 14 mm or any value or range of valuestherebetween or any value that can enable the screw with the threads topass therethrough. Note also that in an exemplary embodiment, the beamscan be curved, as seen in FIG. 6J. Here, beams 631 are presented, andthe beams are curved so as to provide room for the threads of the screwwhile also curving back to interface with the portions of the magnetelements 606 f In an exemplary embodiment, the beams 631 can beconfigured as having to parallel portions at the ends (in fact, in someembodiments, the portions are coaxial with one another), and a curvedportion connecting those two parallel portions together. The endportions can be inserted into the holes that are located in therespective magnet portions as detailed above, thus permitting a straightdrill bores to be drilled into the magnet elements 606F.

In an exemplary embodiment, during construction/assembly, the beams canbe oversized in length, and originally straight/parallel to one another,and then the beams can be bent or otherwise deformed away from oneanother to establish the clearance for the screw. In an exemplaryembodiment, this will draw the magnet portions 606 f towards each other.In an exemplary embodiment, the beams can be oversized in a mannertaking into account this drawing action so that when the beams aredeformed, proper alignment with the magnet elements of the magnet groupare achieved. In an exemplary embodiment, the maximum distance betweenthe two beams is D2, where D2 is less than, equal to and/or greater than0.5, 1.0, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5,9, 9.5, 10, 11, 12, 13, 14, 15, 16, 17, 18 or more mm or any value orrange of values therebetween or any value that can enable the screw withthe threads to pass therethrough. It is also noted that D2/2 can be aradius of curvature of the beams.

With respect to the embodiments where the structure that connects thetwo elements 606 f together is more beefy, such as a plateconfiguration, FIG. 6K presents an exemplary embodiment where a hole 648extends through the center of plate 640. In an exemplary embodiment, thediameter of hole 648 can be greater than, less than or equal to any ofD1 or D2. Any size that will enable the screw to pass through the plate640 can be utilized at least some exemplary embodiments. Note also thatthe hole can be utilized with element 645 as well.

In an exemplary embodiment, the braces collectively and/or individuallyare configured to withstand a tensile and/or a compressive force of 1,1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 or morepounds applied at the peripheries of the magnet portions 606 f.

The above said, in some alternate embodiments, the central magnetelement is a monolithic component and otherwise is a single piecearrangement. FIG. 6L shows an exemplary embodiment of a magnet groupwith magnet portion 606 z. Here a hole 648 extends through magnetportion 606 z, to provide the aforementioned clearance for the screw. Inan exemplary embodiment, hole 648 is around and has a diameter that isgreater than, less than and/or equal to D1 or D2 or any value or rangeof values therebetween. In an exemplary embodiment, the hole 648 is aslarge as possible without reducing the structural integrity of themonolithic magnet portion 606 z. While the hole 648 is depicted as beinground, in an alternate embodiment, it can be rectangular or any shapethat will enable the teachings detailed herein.

The above said, in some embodiments, there is no hole through themagnet(s). FIG. 6M shows an exemplary embodiment of the magnet groupwhere the third magnet portion 606 y is a solid body without any throughholes. Such an embodiment can be utilized with, for example, theimplantable components where the devices that are utilized to fix theimplantable component to the recipient in general, and to bone inparticular, are located away from the magnet. Indeed, in an exemplaryembodiment, the embodiment of FIG. 6M could be utilized in a devicewhere there is no component per se that fixes the apparatus to therecipient. By way of example only and not by way of limitation, animplantable portion of a cochlear implant could be located in arecipient in a manner without any true positive retention of theimplantable portion to the skull. Instead, in an exemplary embodiment,the pressure between the skin in the skull can be utilized to hold theimplantable component in place, or at least the receiver stimulatorthereof. In an exemplary embodiment, an excavation of the like in theskull can be utilized to hold the receiver stimulator in the lateralplane and the skin over the receiver stimulator can be utilized to holdthe receiver stimulator into that excavation.

While the embodiments associated with FIGS. 6A, 6B, and FIGS. 6E-6N havebeen described in terms of three separate magnet portions establishingthe magnet group, other embodiments utilize a monolithic single magnetand/or a magnet that combines at least two of the portions into amonolithic component. In this regard, FIG. 6N depicts an exemplaryalternate embodiment of a magnet portion group that comprises magnetportion 606 d 1, which corresponds to the first magnet portion detailedabove and otherwise has the functionality of magnet 606 d. The magnetgroup also comprises magnet portion 606 c 1, which corresponds to thesecond magnet portion detailed above and otherwise has the functionalityof magnet 606 c. In the middle is the magnet portion 606 f 1, whichcorresponds to the third magnet portion detailed above and otherwise hasthe functionality of magnet 606 f. In an exemplary embodiment, themagnet group 699 is a monolithic disk that has a circular outercircumference and a height of less than, more than or equal to 0.1, 0.2,0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6,1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0,3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, or 10 or 11 or 12 or more mm or anyvalue or range of values therebetween in 0.01 mm increments. Thediameter can less than greater than or equal to 0.5, 1.0, 1.5, 2, 2.5,3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 mmor any value or range of values therebetween in 0.1 mm increments.

While the embodiment of FIG. 6N is presented as a monolithic diskwithout any through hole for the screw 222, in an alternate embodiment,such as depicted in FIG. 6O, through hole 648 is present in themonolithic body of the magnet portion group 699H.

While the embodiments above have focused upon a magnet with a circularouter profile, other embodiments utilize other shaped magnets, such as,for example, rectangular and square-shaped magnets. In this regard. FIG.6P depicts an exemplary embodiment of a magnet portion group 699S, thatincludes magnet portions 606D2, 606 f 2 and 606 c 2, all of which arerectangular in shape as can be seen. The length and/or widths of themagnet group 699S can be any of the above-noted diameters for magnetgroup 699H. It is noted that the monolithic feature of the magnetportions is not limited to the circular cross-section/outer peripheryembodiments. FIG. 6Q presents an exemplary embodiment of a monolithicmagnet group 698S that includes a first magnet portion 606 d 3, a secondmagnet portion 606 c and a third magnet portion 606 f 3, respectivelycorresponding to the portions detailed above in functionality. As withthe embodiments above, the hole 648 is optional.

In an exemplary embodiment, a bushing is located in hole 648 to act as abarrier between the screw 222 and the magnet. This is seen in FIG. 6R,where bushing 655 is located in the hole 648. In an exemplary embodimentbushing 655 is interference fitted into the hole 648. In an alternativeembodiment, it slipped fitted into the hole 648. In some embodiments,the bushing 655 is adhesively retained in the hole or otherwise weldedwithin the hole the bushing can be made of magnetic and/or nonmagneticmaterial.

In at least some exemplary embodiments, the bushing 655 is configured toserve as a barrier between the threads of the screw 222 and the magneticmaterial of the magnet group 697B. In an exemplary embodiment, thebushing 655 can be a barrier to magnetic field flow and otherwise serveas a guide for the diametrically aligned magnetic field that flowsthrough portion 606 f 1. The bushing 655 can be made of PEEK or can bemade of steel or titanium or any material that can have utilitarianvalue (plastic for example). That said, in an exemplary embodiment, thebushing 655 can be its own magnetic body/portion. The bushing 655 cansimply be a sacrificial magnetic body relative to the rest of the magnetgroup 697B.

In an exemplary embodiment, there is a magnet group that includesmagnets and non-magnets, where only the center portion is a magnet. Inthis regard, FIG. 6R1 depicts a magnet apparatus 616 that includesmagnet portions 606 f and nonmagnetic portions 616 c and 616 d. In anexemplary embodiment, these components are identical to the lightcomponents detailed above, while in other embodiments, there are atleast slight differences, such as the nonmagnetic portions 616 c and 616d having sharper edges than magnet portions 606 c and 606 d. In otherembodiments, the sizes can be different. Some additional details will beprovided below, but is noted that any configuration that can enable theteachings detailed herein can be utilized at least some exemplaryembodiments.

As will be described in greater detail below, in an exemplaryembodiment, the nonmagnetic portions are made of material that is notmetallic, and, as will be described in greater detail below, because themagnet apparatus 616 can be located in a housing that is made of anmetallic material, such as a titanium housing, by utilizing anonmetallic material, rattling or otherwise contact between metal andmetal (metal of the magnet portion and metal of the housing) can bereduced and/or eliminated completely (with respect to the latter, thesize of the flanking components (606 d and 606 c) can be oversizedrelative to the central portion and thus support the central portionaway from the housing—in an alternate embodiment, again as will bedescribed below, it is the flanking portions that are metallic and thecentral portion can be oversized to lift up the flanking portions awayfrom the housing).

In an exemplary embodiment, nonmagnetic portions 616 c and 616 d can bemade of plastic or of aluminum or of any other material that can enablethe teachings detailed herein. In an exemplary embodiment, 616 c and 616d can be made of PDFE. Collectively, with the magnet portions, thiscreates a magnet sub-assembly 616 (or magnet apparatus, as is sometimesreferred to herein), which can replace any of the magnets/magnetgroups/magnet subassemblies detailed herein (e.g., 606), and thus hasthe operational/functional features thereof, minus the fact thatportions 616 c and 616 d are not magnetic/not magnets.

In an exemplary embodiment, there can be utilitarian value with respectto using magnet apparatus 616 instead of the magnet groups 606 detailedabove and/or below. Accordingly, any disclosure herein of an embodimentassociated with the magnet group 606 corresponds to a disclosure of anembodiment that utilizes magnet apparatus 616.

Moreover, in an exemplary embodiment, these can be substituted forexisting magnet(s) in existing implants that are of a traditional design(e.g., a magnetic disk having a north-south alignment that is normal tothe direction of the skin). In this regard, in an exemplary embodimentincludes retrofitting existing implanted devices that are implanted inthe recipient with the magnet apparatus 616. Such can be done, by way ofexample only and not by way limitation, before and/or after an MRIprocedure, via a minor surgery that may or may not include explantingthe implant to swap out the magnets.

FIG. 6R2 presents an alternate exemplary embodiment that utilizes magnetportion 606 z, and nonmagnetic portions 616 c and 616 d. The embodimentsof FIGS. 6R1 and 6R2 include passage 621 and 648, respectively, for abolt or the like for attachment to a bone fixture, concomitant with theembodiments detailed above that have this feature as well. That said, inan alternate embodiment, there is no passage. In this regard, FIG. 6R3presents an exemplary magnet apparatus 616 that has a magnet portion 606y that does not have a passage.

It is noted that the embodiments of FIGS. 6R3, 6R4, and 6R5 can utilizeany device, system, and/or method to connect the portions together. Inan exemplary embodiment, any of the connection methods detailed above,such as adhesive, plates, etc., can be used to connect the portionstogether. This is the case with respect to all of the embodimentsdetailed herein unless otherwise noted

The embodiments described above have been presented in terms of having amagnetic polarity alignment with respect to the magnet portion in themiddle that extends across the short axis (at least with respect to theembodiments of FIGS. 6R2 and 6R3). In an alternate embodiment, themagnetic polarity is aligned with respect to the magnet portion in themiddle that extends across the long axis. In this regard, FIG. 6R5depicts an exemplary magnet apparatus 616 that utilizes the nonmagneticcomponents 616 c and 616 d, and magnet 626 y, which has a magneticalignment as shown, which is 90° from the magnetic alignment of theembodiments detailed above with respect to the middle portion. In thisexemplary embodiment, the magnet alignment is in the plane that isnormal to the longitudinal axis of the magnet apparatus (parallel to theskin of the recipient of implanted). FIG. 6R4 presents an alternateembodiment of this concept, except utilizing the magnet portion havingthe passage 648 therethrough. This concept can be further extended toother embodiments, such as seen in FIG. 6R5, where magnet apparatus 616includes magnet portions 626 f, where the magnetic poles of the magnetportions are aligned 90° from that which was the case in the embodimentof FIG. 6R1.

FIGS. 6R7-6R9 depict exemplary embodiments where the middle portion 696z of the magnet apparatus 696/686 is made of the nonmagnetic materialand the flanking portions are magnets. With respect to the magnetapparatus 696, magnet portions 606 d and 606 c of the polarityalignments detailed above with respect to these magnets. However, magnetportion 686 of FIG. 6R9 has the magnet portions 686 d and 686 c alignedin a plane normal to the longitudinal axis of the apparatus/parallel tothe skin of the recipient when implanted therein. For brevity, thevarious ways to implement these embodiments is not shown with respect tosome of the various configurations detailed herein, but it is noted thatany of these features can be combined with any of the other featuresdetailed herein as is consistent with all of the embodiments herein,unless otherwise noted. That is, in an exemplary embodiment, thepolarity alignments of the embodiment of FIG. 6R9 can be utilized withthe embodiments of FIGS. 6R8 and 6R7, and vice versa. 6R9A has anembodiment where all of the magnets have the same polar alignment. Itcan be understood that the magnetic alignment can be opposite from thatdepicted, such as reversed.

FIG. 6R9B presents yet an alternate embodiment where the magnetic polaralignment is different than any of the embodiments described above.Here, there is central component 656 a, which in this case is a magneticcomponent in the form of a permanent magnet, and the magnetic polaralignment of the magnetic polar axis 1234 is neither diametricallyaligned nor axially aligned (where 4321 is the axial longitudinal axis).Instead, the alignment of the poles is obliquely angled relative to thetwo.

More particularly, the magnetic polar axis 1234 is angled by angle thetaaway from the longitudinal axis 4321. In this exemplary embodiment, themagnetic polar axis lies on a plane that is located on the longitudinalaxis 4321 and bisects the central component 656 a at the center thereof.Briefly, it is noted that in at least some exemplary embodiments, therecan be a 2^(nd) degree of orientation from this plane, which will bereferred to as theta2. This is seen in FIG. 6F9C, with respect to theaxis 2341, where the plane of symmetry extends through the axis 2341 inand out of the page, and the magnetic polar axis 1234 is angledtherefrom at theta2. For completeness, FIG. 6R9D presents a side view ofthe embodiment of FIG. 6R9B. It is noted that in the embodiment of FIG.6R9B, the magnetic where axis passes through the geometric center and/orthe mass center of the central component 656 a. That said, in analternate embodiment, the magnetic polar axis 1234 can extend to alocation that is offset from that center. In this regard, the figuresdepict Cartesian coordinate dimensions d17, which extends from the side(establishing the major axis) of the center component 656 a, d19, whichextends from the bottom of the center component 656 a, d23, whichextends from the side (establishing the minor axis) of the centercomponent 656 a, and d25, which extends from the side (establishing themajor axis) of the center component 656 a. The location of the pointestablished by these dimensions can be utilized as the center portion ofthe polar axis 1234/can be used to establish a Cartesian coordinatesystem from which the polar coordinates theta and theta2 can bemeasured.

The values of d17, d19, d23, and d25 can be any value or range of valuesbetween and including and/or less than or greater than 0, 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100 percent of the totaldistance from one side to the other or from the bottom to the top, asappropriate, or any value or range of values therebetween in 0.1%increments, with respect to the component (e.g., if component is 3 mmthick, and d19 is 50% of the total distance from the bottom to the top(min, max, median, mode, etc.), then d19 would be 1.5 mm).

In an exemplary embodiment, the magnetic polar axis can be approximately30, 45, or 60° offset of the angle that is normal to the tangentialplane of the surface of the skin. In this regard, as some embodimentshave utilitarian value with respect to a racetrack shaped magnet or apill or propeller shaped magnet, in that it reduces the friction andhence the torque required to cause a magnet to rotate, this can be anembodiment that enables the magnet axis to be pointed more perpendicularto the skin (and towards the external coil), relative to that whichwould be the case in the absence of the teachings herein. By way ofexample only and not by way of limitation, the magnet axis is pointed atleast 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,40, 45, 50, 55, 60, 65, 70, 75, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%, or any value or rangeof values therebetween in 0.1% increments of a direction perpendicularto the skin relative to that which would otherwise be the case, wherethe percentage is calculated by taking the direction parallel to be 90degrees and using that as the denominator and using the angle away from90 degrees that the axis points minus 90 degrees as the numerator.(90−angle)/90, all multiplied by 100 to get the percentage. With respectto FIGS. 6R9C and 6R9D, the angle theta and theta 2 can be (and the twocan be different), in an exemplary embodiment, equal to, less than, orgreater than 10, 11, 12, 13, 14, 15, 16, 17, 19, 19, 20, 21, 22, 23, 24,25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,79, or 80 degrees, or any value or range of values therebetween in 0.1degree increments.

In an exemplary embodiment, the torque applied to/experienced by themagnet (magnet apparatus/assembly using such) as a result of a 1, 1.5,2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, or 10 T magnetic field from anMRI machine aligned at a direction that is in the plane of FIGS. 6R9 cand/or 6R9 d, or aligned as detailed below, can be reduced by at least5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90,or 95%, or any value or range of values therebetween in 0.1% increments(12.2%, 55.5%, 33.3 to 66.6 percent, etc.) relative to that which wouldbe the case if the angle theta and/or theta2 was zero (parallel to adirection perpendicular/normal to the tangent surface of the skin rightabove the magnet). Other angles of the aforementioned MRI magnetic fieldcan correspond to any of the values of theta and theta2 based on thecoordinates detailed above, where those values can be related to theaforementioned center component or the flanking component (more on thisbelow) and/or can be related to angles off of the overall orientation ofthe implant (e.g., the longitudinal axis (coil to electrode with respectto the CI, for example) would be the equivalent of axis 2341, and theaxis 90 degrees away from that and extending basically normal throughthe skin would be the equivalent of axis 4321.)

FIG. 6R9E depicts an example of where a flanking portion 656 b has theangled polar alignment. Any of the aforementioned features for thecentral portion 656 a can be applicable to this as well, and will not berepeated, but incorporated by reference as applicable to thisembodiment.

Moreover, while the embodiments depicted in the figures have the Northpole extending upwards, it is noted that in alternate embodiments, thereverse can be the case. Moreover, it is noted that consistent with theteachings detailed above, the orientations of the various components canbe different from each other. For example, one side of the flankingcomponent can have the orientation seen in FIG. 6R9E, and the other sideof the flanking component can have the opposite orientation with respectto the North pole being on the bottom. Moreover, the angles can bedifferent for the various components. Indeed, in an exemplaryembodiment, if one was looking at a side view of the magnet apparatus,there could be two or three different polar axes. FIG. 6R9F presents anexemplary embodiment of a hybrid device where the angled polar conceptis used on the flanking magnets and the central magnet is alignedaccording to the teachings at the beginning of the specification(horizontally). FIG. 6R9G presents an alternate embodiment, where thereis a “crisscross” polar axis alignment (the angles are opposite oneanother—it is noted that in an exemplary embodiment, the angles can bedifferent in magnitude).

FIG. 6R9H depicts an exemplary embodiment of the angled pole conceptapplied to a solid disk magnet 666 c where the entirety of the magnetapparatus has the depicted polar axis alignment. It is noted that thiscan be a monolithic embodiment or a divided embodiment, etc. Also, theembodiments of FIGS. 6R9F and 6R9G can be monolithic, where the separateportions are magnetized differently.

Some of the embodiments detailed above can result in a higher externalcomponent retention force compared to a magnetic polarity axis that isparallel to the skin. In this regard, all other things being equal(e.g., for a given magnet volume magnetized in similar manner other thanthe direction of magnetization, the same external component held thesame distance away, the same implant other than the different magnet,etc.) the aforementioned oblique angling of the magnetic pole axis canincrease the retention force by less than, greater than or equal to 10,15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100,110, 120, 130, 140, 150, 160, 170 percent or more, or any value or rangeof values therebetween in 1% increments.

It is noted that in at least some exemplary embodiments, there can beutilitarian value with respect to bonding or attaching the flankingportions to the central portion and/or attaching the central portion tothe flanking portions, depending on whether or not one or more of theseare magnetized, or even if they are all magnetized for that matter, soas to provide support to reduce and/or eliminate the likelihood of themagnet kicking over due to, for example, and unbalanced force and/ortorque. In this regard, there could be utilitarian value with respect toproviding the central portion without the flanking portions and someembodiments. Indeed, to be clear, in at least some exemplaryembodiments, there are implementations where there is only a centralportion and/or only the flanking portions detailed herein or variationsthereof. However, such implementations could, potentially, result in ascenario where the magnet is more likely to rotate about the axis 2341,for example, relative to that which would otherwise be the case if themagnet apparatus was a full circle, for example. Accordingly, there canbe utilitarian value with respect to adding flanking portions to act assomething analogous to outriggers or the like on a boat to betterbalance the magnet as compared to that which would be the case in theabsence of the flanking portions. Alternatively, and/or in addition tothis, the same can be said for the flanking portions—the presence of acentral portion, whether magnetized or not, will provide stability withrespect to that which would otherwise be the case if the flankingportions were located individually in the implant. In this regard, it isnoted that at least some embodiments include the central portion and/orone or more the flanking portions located in the implant/held in theimplant due to being surrounded by the silicone that establishes thebody of the implant. It will be understood that because of therelatively narrow nature of the various individual components of themagnet groups/magnet apparatuses relative to that which would be thecase if the magnet was a complete circle, these components will be morelikely to rotate about the long axis thereof (or even about the shortaxis thereof—the overall space of a circular magnet provides moreresistance to rotation about the short axis relative to that which isthe case with a more narrow magnet). Accordingly, by utilizing theflanking components and/or the central components where otherwise suchmay not necessarily be needed, with respect to establishing a magneticbody, increased stability can be achieved.

Also, in an exemplary embodiment, the flanking portions can reducefriction relative to the housing that might otherwise exist vis-a-visthe magnet of the magnet apparatus contacting the housing with a momentthat is unique to the fact that the magnetization axis is out of theplane of rotation and/or out of the axis of rotation. In this regard, inan exemplary embodiment, the magnet apparatus could cant within thehousing, when exposed to a magnetic field, such as an MRI field, in amanner that is unique because of the oblique angle of the magnetization.By utilizing the flanking portions, such can stabilize the magnetapparatus so as to reduce the amount of canting (owing to the fact thatthe flanking portions can serve as outriggers), or otherwise change thelocation of contact between the magnet apparatus in the housing thatwould otherwise exist, or at least reduce the friction between themagnet apparatus in the housing because the flanking portions are madeof material that has a lower friction coefficient than the magnetapparatus.

Accordingly, in an exemplary embodiments, the utilization of theflanking portions and/or the central portions as opposed to not usingthem, all other things being equal, can result in a reduction of thetotal amount of rotation that would be experienced with respect toexposure to a given magnetic field (whether that is from the MRI or fromthe external component) by at least 10, 15, 20, 25, 30, 35, 40, 45, 50,55, 60, 65, 70, 75, 80, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96,97, 98, 99, or 100%, or any value or range of values therebetween in 1%increments as opposed to that which would exist without the utilizationof the flanking portions and/or the central portions (to establish thecircular body).

It is briefly noted that while the embodiments depicted above havecontemplated the utilization of an adhesive or a plate-like structure,etc., to attach the flanking portions to the central portion, in atleast some embodiments, a tongue and groove like arrangement can beutilized between the central portion and the flanking portions. By wayof example only and not by way of limitation, the flanking portions canbe attached to the central portion in a manner analogous to how cabinetfurniture can be attached. By way of example only and not by way oflimitation, the central portion can have a male tongue on either or bothof the flat sides, and the flanking portions can have a groove thatmates with the respective male tongs, and/or vice versa. Any arrangementthat can enable the teachings detailed herein vis-à-vis attachments ofthe flanking portions of the central portions can be utilized at leastsome exemplary embodiments. In an exemplary embodiment where the centralportion is the magnetic portion, there can be utilitarian value withrespect to making the male tongs part of the central portion as thatincreases the amount of the magnetic material and the magnet apparatus.

In fact, FIG. 6R9I presents yet an alternate embodiment where thecentral portion has components that are more like wings than tongues,which wings that extend outward and into the flanking portions in amanner analogous to the tongue. Here, center portion 676 a is a magnet,and has wings 676 a 1 extending from the center body 676 a 2, intohollows in the flanking portions 676 b. This increases the amount ofmagnetic material relative to that which would be the case (where thecenter portion is a magnetic body) with a more traditional tongue ingroove arrangement. FIG. 6R9J depicts a top view of the embodiment ofFIG. 6R9H. It is noted that in an exemplary embodiment, magneticbolts/dowels 677 can be utilized to secure the flanking portions to thecentral portion, as can be seen. The dowels can be interference fittedinto holes that extend through the flanking portions and the wings ofthe central portion. An exemplary embodiment, the dowels can be belowgrade with respect to tops and bottoms of the flanking portions so as toavoid contact with the housing as will be detailed in greater detailbelow. In an exemplary embodiment, the dowels can be made of magneticmaterial/permanent magnets, thus increasing the amount of magnetmaterial. The alignment of the polarities of these dowels can be anydirection they can have utilitarian value.

In view of the above, there is an implantable medical device, comprisinga magnet apparatus and a body encompassing the magnet apparatus, whereinthe implantable medical device is MRI compatible owing to a magneticaxis of a magnet located in/that is part of the magnet apparatus beingoffset from an axis that is normal to a surface of the skin immediatelyabove the magnet apparatus when the implantable medical devicesimplanted in a recipient. In an exemplary embodiment, the offset between10 to 80 degrees. In an exemplary embodiment, the offset is between 20to 70 degrees, between 40 to 70 degrees or between 50 to 70 degrees,etc. In an exemplary embodiment, the offset is 45, 46, 47, 48, 49, 50,51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68,69 or 70 degrees. As will be described below, in an exemplaryembodiment, the magnet apparatus/magnet is dome shaped.

The embodiments detailed above have presented examples of the magnetapparatus of the implant where the structure of the portions that makeup the apparatus establishes outer circumference of the overallapparatus that is generally uniform. In an alternate embodiment, theshapes of the portions can be different from that detailed above thatresults in a different outer periphery. In this regard, FIG. 6R10depicts a portion 636 a (which can be a magnet portion or a non-magneticportion), in accordance with the teachings above—this disclosure isgenerically presented, and represents an exemplary concept in which toimplement at least some of the teachings detailed herein where thevarious sub component can be filled in with the “like” structuralcomponents presented in the application), that is race track shaped suchthat the outer periphery of portions that are curved have a differentradius of curvature than the portions 636 b (which can correspond to anyof the flanking magnets detailed herein and variations thereof, and canalso can correspond to any of the flanking nonmagnetic portions detailedherein and variations thereof—again, any of the embodiments can beused). In an exemplary embodiment, the radius of curvature of theportion 636 a with respect to the ends thereof, and the radius ofcurvature of the portions 636 b with respect to the outer periphery'sthereof can have a ratio of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9,1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.5, 4, 4.5,5, 6, 7, 8, 9, or 10 or any value or range of values therebetween in0.01 increments (0.23, 3.22, 0.55 to 1.77, etc.). FIG. 6R11 depicts anexemplary magnet apparatus 636, with a center magnet 636 a flanked byflanking magnet/not-magnet portions 636 b. Here, the flanking magnetshave a non-exact non non-full moon shape (there would be a crescent tothe shape, if it was exact or the shape would be half a circle)—thatsaid in some embodiments, the flanking portions can be crescent-shapedand/or half circle shaped—any arrangement that can be utilized topractice the teachings detailed herein and/or variations thereof can beutilized at least some exemplary embodiments. In this embodiment, themoons have a slightly larger dimensioned relative to the racetrackshaped center portion. FIG. 6R12 depicts a side view of the embodimentof FIG. 6R11. As seen, the portions are all aligned at the top andbottom. In an alternate embodiment, as seen in FIG. 6R13, which can bean alternate embodiment of FIG. 6R11, the flanking portions extendbeyond the tops and bottoms of the middle portion. FIG. 6R14 depicts analternate embodiment, where the flanking portions only extend past thebottom (in an alternate embodiment, they only extend past the top). FIG.6R15 depicts an alternate embodiment where the bottom portions of theflanking portions extend out past the bottom portions of the centerportion, but the top portions of the flanking portions are below the topportions of the center portion (or vice versa in an alternateembodiment). FIG. 6R16 depicts an alternate embodiment where the bottomportions of the flanking portions and the top portions of the flankingportions are above and below, respectively, the portions of the centerportion.

In an exemplary embodiment, referring to FIG. 6R17, the collectiveextrapolated outer diameter 170 (which should be quasi perfectlycircular, but can instead be oval, etc., in other embodiments, in whichcase it is the maximum extrapolated outer diameter) of the flankingportions is at least X % larger than the maximum and/or extrapolateddiameter 172 of the center portion 363 a and/or at most X % larger orsmaller than the maximum and/or extrapolated diameter 172 of the centerportion 363 a. X can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9,1.0, 1.25, 1.5, 1.75, 2.0, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5,8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 45,50, 55, or 60, or any value or range of values therebetween in 0.01increments. Thus, the diameter can be, for example, at least 1.5 percentlarger and at most 2.5 percent larger than the center portion. As can beseen above the flanking portions can also extend above and/or below thetop and/or bottom of the center portion, and/or can be located below thetop or above the bottom of the center portion, and can do so such thatthe total extension and/or the specific extension above and/or belowand/or the “retraction” can be at least X % of the thickness of thecenter portion. The distances can also be at most X % of the thicknessof the center portion, such as, for example, no more than 0.4% of thethickness, and no more than 0.7% of the thickness. The magnet apparatuscan be symmetrical about any plane, and/or can be asymmetrical about anyplane. The aforementioned heights can be different for the top or thebottom.

By making these partially circular segment flanking portions slightlylarger in height and/or effective radius, relative to the centralportions, the partially circular segment material will always be incontact with the housing (this can ensure or increase the likelihood ofa smooth rotation and/or securement of the magnet apparatus, as will bedetailed below). Alternatively, or in addition to this, by making thediscorectangular central portion slightly larger in height and/or ineffective radius, relative to the flanking portions, the discorectangular central portion will always be in contact with the housing(and this too can ensure increase the likelihood of a smooth rotationand/or securement of the magnet apparatus, as will be detailed below).

FIG. 6R18 presents an alternate embodiment of an apparatus 646 where abar central portion 646 a is utilized instead of a racetrack shapedportion, and the flanking portions 646 b are attached to the lateralsides of the bar shaped portion. As with the embodiments above, thecentral portion 646 a can be a magnet and/or magnetic material and inother embodiments it is not a magnet, such as embodiments where thematerial is PEEK or PDFE, etc., or a generic plastic. Also, in someembodiments, the flanking portions 646 b can be magnet/magneticmaterial, while in other embodiments it is not a magnet or a magneticmaterial.

In the embodiment of 6R18, the bar shaped portion is recessed withrespect to the extrapolated outer periphery established by the flankingportions. However, FIG. R19 presents an alternate embodiment where suchis not the case. In this regard, the bar shaped portion 646 a is amaximum diameter that corresponds to the diameter of the flankingportions immediately proximate the bar shaped central portion. Thatsaid, FIG. 6R20 depicts another exemplary embodiment where the barshaped central portion 646 a extends past the diameter of the flankingportions immediately proximate the bar shaped portion. In an exemplaryembodiment, the bar shaped portion can establish the maximum outerdiameter, as shown in FIG. 6R20, where the dashed line represents anextrapolated outer profile of the magnet apparatus. Conversely, as seenin FIG. 6R21, a bar shaped central portion which extends past theflanking portions can still be within the extrapolated outer profile ofthe apparatus, which outer profile is established by the maximumdiameter established by the flanking portion.

In an exemplary embodiment, both the central portion and the outerportion can be flush with the extrapolated outer profile, even if thecentral portion is a bar shaped central portion.

In an exemplary embodiment, the maximum diameter of the central portioncan be X % greater or less than the maximum diameter that corresponds tothe distance from one side of flanking portion to the other side of theopposite flanking portion.

FIG. 6R22 presents an exemplary embodiment of a laterally larger centerportion 636 a that can be utilized, where the center portion 636 aextends into the flanking portions 646 b as seen. Any shaped or sizedcentral portion that can have utilitarian value can be utilized in atleast some exemplary embodiments. FIG. 6R23 depicts another exemplaryembodiment where the flanking portions can be bifurcated into separatecomponents and fit about the central portion. In the embodimentdepicted, each of the flanking portions 646 b are divided into threesub-portions. FIG. 6R24 depicts another exemplary embodiment where thecentral portion vastly dominates the flanking portions, where theflanking portions are nonoverlapping. In this exemplary embodiment, thelateral sides of the central portion extend past the inside lateralsides of the flanking portions. Conversely, FIG. 6R25 is such that thelateral sides of the central portion do not extend past the insidelateral sides of the flanking portions.

In view of the above, it can be seen that in an exemplary embodiment,there is an implantable medical device, comprising a magnet and a bodyencompassing the magnet, wherein the magnet is racetrack shaped. In anexemplary embodiment, the racetrack shaped magnet is located in aracetrack shaped housing. In an exemplary embodiment, the racetrackshaped magnet is attached, either directly or indirectly, to flankingportions in the shape of partial moons on either side thereof. In anexemplary embodiment, the racetrack shaped magnet is located in ahermetic housing.

In an exemplary embodiment, the implantable medical device describedabove has a racetrack shaped magnet that has a magnetic axis that isoffset from a vertical axis that is parallel to the skin of therecipient when the implantable medical devices implanted in therecipient. In an exemplary embodiment, the racetrack-shaped magnet has amagnetic axis that is offset by an amount that is 10 to 80 degrees froma vertical axis that is parallel to the skin of the recipient when theimplantable medical devices implanted in the recipient. In an exemplaryembodiment, the racetrack-shaped magnet has a magnetic axis that isoffset by an amount that is 30 to 70 degrees from a vertical axis thatis parallel to the skin of the recipient when the implantable medicaldevices implanted in the recipient.

As noted above, some embodiments can utilize a bushing 655. The bushing655 can be a bearing or part of a bearing that can enable the magnetgroup to spin/revolve. FIG. 6S depicts an exemplary embodiment of such.Here, there is an outer race 665 of a ball bearing apparatus that can beinterference fitted or otherwise adhesively fitted or welded etc. intothe hole through the magnet group. There is also an inner race 666 andball bearings 667. The ball bearings permit the inner race, or, moreaccurately, the outer race (because the inner race is typicallyfixed—more on this below) to move relative to the inner race withrelative ease, thus permitting the magnet group to rotate/revolve withgreater ease than that which would otherwise be the case. In anexemplary embodiment, the bearings are lubricated and can be a thrustbearing apparatus so that the bearing supports the entire magnet groupaway from the housing wall in embodiments where the magnet is located ina housing.

FIG. 6T1 presents an exemplary embodiment of the utilization of thebushing 655. In this embodiment, the bushing 655 is a compound bushingthat has a portion that accepts the head of the screw 222 that the topsurface is generally flush. That said, in an alternate embodiment, anormal cylindrical bushing with constant inner and outer diameters canbe used such as that seen in FIG. 6T2, where the bushing 655 is inside ahousing 687, and the screw head of screw 222 or other components closethe housing and hermetically seal or otherwise isolate in a utilitarianmanner the magnet group 697B from the ambient environment. This ascontrasted to the embodiment of FIG. 6T1, where the magnet group 697B iscoated with a biocompatible coating that isolates the magnetic materialof the magnet portions from the ambient environment.

With reference to the variation of the embodiment of using a bearing,such as a thrust bearing apparatus, instead of the mere utilization of abushing, FIG. 6T3 depicts a side view of such an exemplary embodiment.Here, the bearing apparatus is inside a housing 687, where the innerrace 666 is interference fitted or slipped fitted or welded or otherwiseadhesively bonded to the inner wall of the housing 688 that extends fromthe bottom of the housing to the top of the housing (the central innerwall can be a cylindrical structure that extends from the bottom of thehousing to the top of the housing and can be monolithic with one ofthose components and welded to the lid (or bottom) of the housing toestablish the hermetic seal—the inner race 666 can be slipped oversuch—it is noted that this configuration can also be utilized with thebushing 655 above—the bushing can be slip fit or interference fitted orotherwise adhesively attached or not attached to the inner cylindricalwall of the housing, and the lid or bottom can be welded to thecylindrical wall to establish the hermetic seal). Here, a roller bearing667 is utilized instead of a ball bearing as disclosed in the embodimentabove—any bearing that can enable the teachings detailed herein can beutilized at least some exemplary embodiment. The outer race 665 isinterference fitted or slipped fitted or otherwise attached to themagnet group in general, and the third magnet portion 606 f 1 or thegroup thereof in particular). The screw head of screw 222 extends to thecylindrical wall of the housing 668 so as to secure the housing 668, andthus the magnet group therein, to a bone fixture to bone of therecipient, etc. In an exemplary embodiment of this embodiment, thebearing apparatus provides an arrangement that permits the magnet groupto rotate about the screw 222 or otherwise about the cylindrical innerwall of the housing in a low friction manner. In an exemplaryembodiment, the area inside the housing can be filled with a lowviscosity lubricant, such as a biocompatible oil or the like. Thebearings can be lubricated or non-lubricated.

The above said, in at least some exemplary embodiments, the magnet groupcan rotate or otherwise spin about the bushing/the bushing can rotate orotherwise spin about the inner cylindrical housing wall and/or thescrew. The bushing can be made of a low friction material that willresult in low friction with respect to the inner and/or the outersurface thereof, thus permitting the magnet group to rotate with orwithout rotation of the bushing. In an exemplary embodiment, a lubricantcan be located on the inner surface and/or the outer surface of thebushing to enhance rotation of the magnet.

Thus, in an exemplary embodiment, the implantable apparatus can beconfigured such that it enables the magnet group to rotate as a unitrelative to the housing about an axial direction. In some exemplaryembodiments, the magnet group has a hole extending through the group,and a bearing body is located in the hole, the bearing body being usedto guide rotation of the magnet group.

FIG. 20A presents an exemplary embodiment of a magnet apparatus 2001that includes a magnet 2010 (which can be instead a magnet group and/ora magnet apparatus/magnet sub-assembly as describe above and/orbelow—any disclosure herein of a magnet and/or magnet group correspondsto a disclosure of an alternate embodiment where there is a magnetapparatus and/or a magnet group as disclosed herein, and vice versa,unless otherwise noted or unless the art does not enable such—more onthis below) located in a housing 2020 that hermetically isolates theinterior of the housing from the outside environment. The housing can bea titanium housing, or can be another type of metallic housing, and/orcan be a ceramic housing and/or can be a plastic based housing, etc. Anyhousing that can enable the teachings herein can be utilized in someembodiments. In an exemplary embodiment, a lubricant 2030, such as afluid lubricant, is located inside the housing, and otherwise, incombination with the magnet, fills the interior of the housing orotherwise substantially fills are effectively fills the interior of thehousing. In an exemplary embodiment, this results in a design frictionthat is low. This enables the magnet 2010 (or magnet apparatus) torotate within the housing relatively easily. In an exemplary embodiment,the magnet 2010 can instead be a magnet group according to any of theteachings detailed herein. In an exemplary embodiment, such as wherethere are three separate magnets, the magnet group can be encased in asecond housing (not shown) or in a membrane or in a sealed environmentto isolate the magnet components from the fluid inside the housing. Notealso that in some embodiments, the extra-membrane or the sealing or theextra housing can also be utilized with the monolithic magnet as well.

In an exemplary embodiment, such as by way of example only and not byway of limitation, where the housing includes a fluid lubricant, therecan be utilitarian value with respect to encasing the magnet apparatusin a secondary housing. In an exemplary embodiment, there is a housingthat includes the center portions and the two flanking portionsaccording to any of the embodiments detailed herein, and this housingcan be sealed or the like, and then the housing including the center andflanking components can be placed into the outer housing (e.g., housing2020), and then the inner housing can move relative to the outerhousing. In an exemplary embodiment, the center and flanking portionscan be interference fitted or slipped fitted or clearance fitted intothe inner housing. The components can be secured in the inner housingany manner that can have utilitarian value with respect to implementingthe teachings detailed herein. In an exemplary embodiment, an epoxy thelike can be used to fill the inside of the interior housing and thus“lock” the center portions of the flanking portions in the inside of thehousing.

The above said, in an alternate embodiment, the magnet apparatusesdetailed herein can be placed inside the housing 2020 without thosecomponents being located in a separate housing.

In an exemplary embodiment, the components of the magnet apparatuses canbe coated, either individually or collectively, with a substance, suchas a polymer or the like, and then the coded components can be locatedin the housing 2020.

All of the above said, in some embodiments, there is utilitarian valuewith respect to preventing the magnet group (or magnet or magnetapparatus, etc., as noted above) from rotating within the housing 2020(or any other housing disclosed herein, such as housing 688) where thehousing does not rotate, either. This can be because, by way of exampleonly and not by way of limitation, the orientation of the magnetic fieldrelative to the skull is desired to be aligned in a consistent mannerthat is maintained for a long period of time, such as 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,26, 27, 28, 29 or 30, or 35 or 40 or 45 or 50 or 55 or 60 years or moreor any value or range of values therebetween in one day increments. Theorientation could be desired to be maintained for the life of therecipient. The orientation could be designed to be maintainedirrespective of the exposure of the recipient to a magnetic field, atleast some magnetic fields of at least limited strengths, such as, forexample, the magnetic field resulting from the external magnet of theexternal component. Still further, in an exemplary embodiment, theorientation could be maintained when subjected to a high strengthmagnetic field, such as, for example, the magnetic field of an MRIdevice, which can be 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7,8, 9 T or more. Some exemplary scenarios of this will be described indetail below. The point is, in at least some exemplary embodiments, thearrangement is configured so as to provide friction or otherwise preventor otherwise limit the rotation of the magnet group (or any magnet thatis utilized, for that matter, whether it is a magnet group or a magnethaving polarity that is uniform).

In an exemplary embodiment, the exposure to the magnetic field takesplace at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30, or 35 or 40 or45 or 50 or 55 months or years after implantation of the magnet. In anexemplary embodiment, the magnet has at least never effectively neverrotated relative to the implanted medical device prior the exposure tothe magnetic field. That said, in an alternative embodiment, the magnethas rotated by at least X amount at least Y number of times during thatperiod, were Y is a number that is equal to 5, 10, 15, 20, 25, 30, 35,40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90 or 95 percent of the numberof days since implantation. The variable X can be any of 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40 or 45 degrees ormore or any value or range of values therebetween in 1% increments (andcan be different for every occurrence and can be the same for some anddifferent for others) again be positive or negative—this is simply achange from one change to the next.

Thus, in an exemplary embodiment, the orientation of the magnet groupaccording to some methods has remained at least substantially constantand/or effectively constant from the time of implantation of theimplanted device to the time at least just before exposure to themagnetic field.

It is noted that while the embodiments depicted in FIGS. 606T2 and 606T1utilize the monolithic magnet group, other embodiments utilize theseparate components according to the other teachings detailed hereinwhere they are adhered otherwise supported are held together accordingto any of the teachings detailed herein or other variations.

In accordance with the teachings above, it is noted that the embodimentsdisclosed herein that utilize the magnet groups and/or magnetapparatuses, etc., provide enhanced magnetic attraction relative to thatwhich would otherwise be the case for a similarly situated magnet. Inexemplary embodiments, this can result in the magnet on the outsidebeing smaller than that which would otherwise be the case to achieve thesame magnetic force. This is utilitarian in that the external componentcan be lighter and smaller than that which would otherwise be the case.Alternatively, and/or in addition to this, a stronger magneticattraction can be established between the external component and theimplant. In any event, there is the possibility that the implantedcomponent can come into contact with a stronger magnet of an externalcomponent or otherwise experience a stronger magnetic field, such as inthe case of an MRI, and this might dislodge the implanted component orotherwise impart a torque onto the implant that could cause discomfortto the recipient because skin tissue is resisting/counteracting thetorque. Accordingly, the teachings detailed herein with respect toholding the magnet utilizing the screw 222 can be utilitarian. While theembodiments detailed above focused on utilizing a screw to hold themagnet group for a passive transcutaneous bone conduction deviceaccording to FIG. 2 above, it is noted that this embodiment can beutilized for the other types of implantable components, such as forexample, the implantable portion of the cochlear implant and theimplantable portion of the active change continues bone conductiondevice. For example, FIG. 6U presents the implantable component of thecochlear implant 300, where the magnet group/magnet apparatus/magnet697B is located in the silicone body, and the magnet group/magnetapparatus/magnet 697B is held to the skull via screw 222 (directly orinto a bone fixture). This embodiment can have utilitarian value withrespect to maintaining the overall position of the implantable portionduring both normal usage and with respect to exposure to high magneticfields such as, for example, that which could result from the exposureof the recipient to an MRI. To be clear, element 697B can be any of themagnets/magnet groups/magnet apparatuses disclosed herein or variationsthereof and can be utilized in conjunction with a housing as detailedabove and/or below, or without a housing.

Accordingly, in an exemplary embodiment, the teachings detailed hereincan be utilized to maintain a position of the magnet/magnet group/magnetapparatus relatively globally stationary when a magnetic field isapplied to the magnet portion of the group/apparatus, etc., at issue,that results in a force that is normal to the longitudinal axis of themagnet group/magnet and away from the skull and/or that is parallel tothe longitudinal axis of the magnet group/magnet and thus parallel withthe skull of less than, greater than or equal to 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, or more Newtons or anyvalue or range of values therebetween in 0.1 N increments. With respectto the phrase “globally stationary,” it is noted that in at least someembodiments, the magnet group can spin or rotate, such as spin withinthe housing, and thus the magnet group will be locally movable but willnot move relative to its overall position adjacent the skull, etc.Indeed, it is noted that the embodiments described above can beimplemented with a housing that has a through hole for the bolt. In thisregard, in an exemplary embodiment, there can be a donut-shaped housingor the like that houses the magnet group and/or the magnet apparatus,where the hole of the magnet apparatus extends about the cylindricalpassageway through the center of the housing, such that the inside thehousing can be hermetically sealed from the external environment whilethe bolt extends through the housing from one side to the other toattach to the fixture, and thus secure the magnet/magnet group/magnetapparatus.

The above said, embodiments include implant components, such as cochlearimplant 300, or, for that matter, receiver stimulators of stimulatingprostheses, such as middle ear implants, or bionic eye implants, passivetranscutaneous bone conduction devices, etc. (teachings herein areapplicable to any such devices or any implantable device unlessotherwise noted or otherwise not enabled by the art), that are notaffirmatively anchored to the skull of the recipient, or at least do notutilize the bone fixture arrangement detailed above (instead, lesssubstantial screws might be utilized, for example). In some suchembodiments, the receiver stimulator is simply located between the skulland the skin and the natural pressure of the skin on the skull holds thereceiver stimulator relatively in place, or, in some embodiments, ashallow cavity or more than a shallow cavity is cut into the skull, andthe receiver stimulator is located therein. In any event, in at leastsome exemplary embodiments, the magnet group or magnet apparatus, etc.,is not bolted to the skull or otherwise directly attached to the skull.

FIGS. 6U1 and 6U2 presents some exemplary embodiments of such anexemplary embodiment. Here, magnet group 606, which can correspond tothe arrangement of FIG. 6M above, by way of example only and not by wayof limitation, or the magnet apparatus 636 of FIG. 6R10 can be utilized,again by way of example only and not by way of limitation (any magnetgroup or apparatus or magnet disclosed herein can be utilized in theembodiments of FIGS. 6U1 and 6U2—these are simply specific examples forpurposes of discussion) as the implanted magnetic component. In thisexemplary embodiment, the magnet apparatus 606/636 is held within thesilicone body 170 by direct contact therewith by the silicone (or bydirect contact with a housing housing the components of 606/636, inembodiments where the magnet components/portions of the groups/apparatsare housed in a housing—again, any disclosure herein of a magnet groupand or magnet apparatus and/or a magnet corresponds to a disclosure ofan embodiment where that group/apparatus/magnet is housed in a housing,consistent with the fact that any teaching herein can be combined withany other teaching herein unless otherwise noted providing the artenable such) of the body 170. Note that this is not mutually exclusivewith the embodiment of FIG. 6U, where the silicone of the body is alsoin direct contact with the magnet group/housing thereof—there is justalso a bolt that extends through the magnet group as shown above. Thatsaid, in some embodiments of the teachings of FIG. 6U, the silicone bodyis purposely away from the magnet group/magnet apparatus, as seen inFIG. 6U3, where boundary 171 is present completely and circling theboundary of the magnet 697B. in an exemplary embodiment, this can enableeasy removal of the magnet 697B without disturbing the overall receiverstimulator. Accordingly, embodiments include implants where the siliconeof the silicone body is purposely not in contact with any portion of themagnet/magnet group/magnet apparatus and/or housing thereof.

The above said, in some embodiments, the arrangement of FIG. 6U3 can besuch that the boundary 171 of the silicone abuts the outer circumferenceof the magnet group and/or housing thereof. In this exemplaryembodiment, there is no silicone above and/or below the magnetgroup/housing. This can enable removal of the magnet 697B withoutdisturbing the overall receiver stimulator, while still providing amaximum of silicone to support the coil 137.

In an exemplary embodiment, the boundary 171 is less than greater thanor equal to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2,1.3, 1.4, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, 3, 3.5, 4, 4.5, or 5 mm orany range of values therebetween in 0.01 mm increments away from theouter circumference of the magnet group/housing thereof. Conversely, inan exemplary embodiment, the boundary 171 establishes an interferencefit or a slip fit with the magnet apparatus/housing thereof.

It is noted that while the embodiment of FIG. 6U3 is presented in termsof the utilization of bolt 222, while in other embodiments, thearrangement of FIG. 6U three is combined otherwise utilized with theother embodiments without a bolt.

Still, with respect to the embodiments that utilize the silicone of thebody 170 to support the magnet group in its entirety, in an exemplaryembodiment, again, the only thing that is in contact with the magnetgroup/housing thereof is the silicone of the silicone body. In anexemplary embodiment, the implantable component 300 is configured so asto resist movement of the magnet apparatus/magnet group/magnet, housedor otherwise, about the longitudinal axis thereof (the axis extending inand out of the plane of FIG. 6U1, by way of example). Some additionalteachings of this will be described in greater detail below. Brieflyhowever, if the magnet is housed in a housing, in this exemplaryembodiment, the magnet-housing combination is such that the magnet willnot move relative to the housing, at least not without great difficultyor otherwise breaking a component thereof. In an exemplary embodiment,if the magnet is housed in a housing, any movement of the magnet willalso correspond to an equal movement of the housing—that is, to theextent anything moves, it is the housing that moves with the magnet(e.g., in a one to one relationship), owing to a torque placed onto themagnet via a stronger magnetic field, such as an Mill field. If thehousing is not present, it is the magnet that moves. The aforementionedmovement can be rotation about the longitudinal axis just detailed. Inthese exemplary embodiments, to the extent there is movement, ismovement that is due because the magnet group/magnet apparatus/magnet,or the housing thereof, experiences a torque that is high enough toovercome the friction forces between the silicone body and the pertinentcomponents of the magnet group.

Accordingly, in an exemplary embodiment, there is an implant that isconfigured such that the magnet group/magnet apparatus/magnet, whetheror not housed, thereof, will resist rotation about the longitudinal axisthereof/not rotate when subjected to a torque about the longitudinalaxis of less than, greater than or equal to 0.1, 0.15, 0.2, 0.25, 0.5,0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30,35, 40, 45 or 50 or 60 or 70 or 80 or 90 or 100 or more inch-pounds orany value or range of values therebetween in 0.05 inch-pound increments.The above said, as with all structures, there is always a certain amountof flexure that exists. In this regard, a concrete block will flex evena limited amount when a person sits on such. Accordingly, it is to beunderstood that there will be some flexure of the silicone body when theaforementioned torques are applied, and thus some movement, such asrotation, of the magnet group/housing thereof. Accordingly, in anexemplary embodiment, there is an implant that is configured such thatthe magnet group/magnet apparatus/magnet, whether or not housed, doesnot rotate more than 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.25, 2.5, 2.75, 3,3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9,9.5, 10, 11, 12, 13, 14 or 15 degrees or any value or range of valuestherebetween in 0.01° increments when exposed to a torque about thelongitudinal axis of less than, greater than or equal to 0.1, 0.15, 0.2,0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5,5.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 30, 35, 40, 45 or 50 or 60 or 70 or 80 or 90 or 100 or moreinch-pounds or any value or range of values therebetween in 0.05inch-pound increments.

FIG. 6U4 presents another exemplary embodiment where the magnetapparatus includes arms 176 extending from the circumference of thehousing of the magnet apparatus, which arms extended into the siliconebody 170, and provide further reaction surfaces beyond that which wouldbe the case with respect to the embodiments detailed above againstrotation of the housing (or magnet group/magnet apparatus embodimentswhere there is no housing). In this regard, this embodiment providesadditional anti-rotation features relative to that which is the casewith respect to the silicone on the outer circumference of a cylindricalbody such as the embodiments detailed above. Here, arms 176 extendgreater than less than or equal to 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3,3.5, 4, 4.5, 5, 6, 7, 8, 9 or 10 mm or more away from the circular wallof the outer circumference of the housing or magnet apparatus, anequivalent length into the body 170. The silicone body 170 envelopsthese arms and thus provides additional reaction against rotation. Forarms are shown in this embodiment, but in other embodiments, fewer morearms can be utilized. By way of example only and not by way limitation,one, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13,14, 15 or more arms can be utilized at least some embodiments. Also, itis noted that in at least some exemplary embodiments, the housing of themagnet apparatus and/or the magnet apparatus or group etc., can berigidly connected to component 122, so as to provide additionalantirotation features.

In at least some exemplary embodiments, the height of the arms 176 areabout the same as the heights of the housing of the magnet apparatus andwhere the magnet apparatus, etc. In some embodiments, the height of thearms can be larger while in other embodiments, the height can besmaller. FIG. 6U5 presents an exemplary embodiment where the armsactually extend above and below the housing of the magnet apparatus.Here, arm 176′ extends from one side of the housing to the other side ofthe housing, and has a component that extends over the housing as well(and below, but such cannot be seen). In an exemplary embodiment, theheight of the arm 176′ (or 176, for that matter) can be such that it iscompletely enveloped in the silicone body above and below, while inother embodiments, at least a portion of the arm may extend through thesilicone body/not be enveloped by the silicone body.

It is noted that while the embodiments detailed above have beenpresented with the slit 180 present, in some embodiments, the slit 180is not present.

In any event, it is noted that embodiments include any of the magnetapparatuses disclosed herein or variations thereof housed in a housing,where the magnet apparatus (group or single magnet, etc.) is configuredto not rotate relative to the housing, when the magnet apparatus issubjected to a torque about the longitudinal axis of the magnetapparatus of less than, greater than or equal to 0.1, 0.15, 0.2, 0.25,0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,30, 35, 40, 45 or 50 or 60 or 70 or 80 or 90 or 100 or more inch-poundsor any value or range of values therebetween in 0.05 inch-poundincrements. Further, in an exemplary embodiment, there is an implantthat is configured such that the magnet group/magnet apparatus/magnetdoes not rotate, relative to the housing more than 0.1, 0.2, 0.3, 0.4,0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8,1.9, 2.0, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75, 5,5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14 or 15 degrees orany value or range of values therebetween in 0.01° increments whenexposed to a torque about the longitudinal axis of less than, greaterthan or equal to 0.1, 0.15, 0.2, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2,2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45 or 50 or 60 or 70or 80 or 90 or 100 or more inch-pounds or any value or range of valuestherebetween in 0.05 inch-pound increments. Corollary to the above isthat in some embodiments, there is a magnet apparatus/group that rotatesin a one to one relationship with the housing relative to the rest ofthe implant when exposed to a sufficient torque that will cause themagnet apparatus and the housing to rotate relative to the implant.

It is briefly noted that the embodiment of FIG. 6U1 differs from theembodiment of FIG. 6U2 in the orientation of the magnet group 606/636.In the embodiment of FIG. 6U1, the central portion of the magnet grouphas its long axis parallel to the longitudinal axis of the implant,while in the embodiment of FIG. 6U2, central portion of the magnet grouphas its long axis perpendicular to the longitudinal axis of the implant.In an exemplary embodiment, the orientation of the central portionvis-à-vis the long axis thereof can be 0, 5, 10, 15, 20, 25, 30, 35, 40,45, 50, 55, 60, 65, 70, 75, 80, 85 or 90 degrees any value or range ofvalues therebetween in 1° increments from the longitudinal axis of theimplant. It is also noted that these orientations can be applicable forany of the alternative embodiments associated with a multi-componentmagnet apparatus—any definable axis of the magnet apparatus can bealigned, relative to the longitudinal axis, according to theaforementioned values, and in some embodiments, this alignment can beintended to be permanent (i.e., the magnet apparatus is configured notrotate relative to the rest of the implant).

FIG. 6V presents another exemplary embodiment of an implantablecomponent of a hearing prosthesis, the implantable component of anactive transcutaneous bone conduction device 499. Here, the receiverassembly 456 includes an RF coil 137 that is supported by or otherwiseencased in a silicone body 970, and magnet group 697B that is alsoencased in the silicone body 970. The magnet group 697B is bolted to theskull via screw 222. Because this embodiment utilizes a separate housingthat contains the vibrating actuator (component 453), a second screw 222is utilized to hold that component down against the skull. As can beseen as represented by the two-way arrow, the coil 137 is in signalcommunication with component 453, consistent with the teachings detailedabove in regard to an active transcutaneous bone conduction device.

Still further, as can be seen, at least some exemplary embodiments areconfigured to be implanted into a recipient without intent to beremoved. In some instances, there is intent to not remove the magnetgroup even when exposed to high strength MRI fields. In someembodiments, there are methods that include exposing the recipient'shead to at least about (and including a 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5,5.5, 6, 7, 8 9 T or more MRI magnetic field without removing the magnetgroup from the recipient. In some embodiments, this is done withoutapplying any additional restraints, such as a bandage and/or splint tohold the magnet in place. Indeed, in an exemplary embodiment, the screw222 eliminates any need for such.

Accordingly, now with reference to FIG. 12 , which presents an exemplaryflowchart for an exemplary algorithm for an exemplary method, method1200, there is an exemplary method in an exemplary embodiment, there isan exemplary method that includes method action 1210 which includesobtaining access to a recipient of a medical device including a magnetgroup implanted in the recipient. Method 1200 also includes methodaction 1220, which includes exposing the recipient and the magnet groupto an MRI field of at least 2.5 T without removing the magnet group. Ina variation of this method, the MRI field is at least 1, 1.5, 2, 2.25,2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75, or 5 T or any valueor range of values therebetween in 0.1 T increments.

In an exemplary embodiment of this method, consistent with the teachingsdetailed above the magnet group is positively retained to the skull viaa screw, such as screw 222. Also, as noted above, in at least someexemplary embodiments, there is no external component that appliespressure to the skin or otherwise holds the magnet in place, such as abandage or a splint. In at least some exemplary embodiments, this isenabled via the utilization of the screw 222. In an exemplaryembodiment, when the magnet group is subjected to the aforementionedfields, the global position of the magnet changes no more than 0.05,0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.175 0.2,0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 mm measured ata given point relative to that which was the case prior to exposure tothe aforementioned magnetic field. In an exemplary embodiment, therecipient is wearing nothing on his or her head during the entire timeof exposure to the aforementioned MRI field strengths.

Accordingly, now with reference to FIG. 13 , which presents an exemplaryflowchart for an exemplary algorithm for an exemplary method, method1300, there is an exemplary method in an exemplary embodiment, there isan exemplary method that includes method action 1310 which includesobtaining access to a recipient of a medical device including a magnetgroup implanted in the recipient. Method 1300 also includes methodaction 1320, which includes exposing the recipient and the magnet groupto an MRI field of at least 2.5 T without removing the magnet group andwithout anything being worn on the recipient's head or attached to therecipient's head. In a variation of this method, the MRI field is atleast 1, 1.5, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75or 5 T or more any value or range of values therebetween in 0.1 Tincrements.

An exemplary method also includes implanting the implantable componentinto the recipient. Accordingly, now with reference to FIG. 14 , whichpresents an exemplary flowchart for an exemplary algorithm for anexemplary method, method 1400, there is an exemplary method in anexemplary embodiment, there is an exemplary method that includes methodaction 1410 which includes implanting a medical device with a magnetgroup in a head of the recipient. In an exemplary embodiment, this isexecuted by cutting into the recipient at a location above the mastoidbone or other skull bone and placing any of the implantable medicaldevices disclosed herein or variations thereof or other medical devicesinto the opening. In an exemplary embodiment where the magnet group isscrewed to bone, an exemplary embodiment includes placing a torqueapplying device, such as a screwdriver an Allen wrench, etc. through aslit in the silicone that covers the magnet group. By way of exampleonly and not by way of limitation, with respect to FIG. 6W1, it can beseen that in an exemplary embodiment of the implantable component 300 ofthe cochlear implant, there is a slit 180A that extends through thesilicone body 170 that encases the magnet group 697B. in an exemplaryembodiment, the implantable component 300 can be placed over a bonefixture and the screw 222 is aligned with the bone fixture, and thetorque is applied to the screw 222 using the tool extending to the slit180A to screw the screw 222 into the bone fixture and thus secure andotherwise fix the magnet group 697B to the skull. In an exemplaryembodiment, the silicone body is formed around the magnet group (and ahousing if the magnet group is located in the housing), such that thescrew 222 extends through the bottom of the silicone body. In anexemplary embodiment, the slit is large enough so that the tool can passthrough, but no more. This is because the magnet group 697B is notintended to be removed from the implantable component 300 during thelife of the implantable component, at least not while the implantablecomponent is implanted into the recipient. That is, to the extent thatthe magnet group 697B is to be removed from the head or otherwise bodyof the recipient, the screw 222 is unscrewed from the bone (bonefixture) and the entire implantable component is removed.

That said, in some alternate embodiments, the implantable component 300is configured so that the magnet group 697B can be removed (along with ahousing if the magnet group is located in a housing) from theimplantable component 300 while the implantable component remains in therecipient's head or otherwise in the body. In this regard, in anexemplary embodiment, referring now to FIG. 6W2, there is a larger slit180B that is large enough to enable the magnet group 697B and anyhousing associated there with to be removed from the silicone body 170when the screw 222 is unscrewed. In an exemplary embodiment, theaforementioned slits are, in length less than, equal to or greater than70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, or145 percent, or any value or range of values therebetween in 1%increments of the maximum and/or minimum diameter normal to thelongitudinal axis of the screw and or the tool that is utilized tounscrew or screw the screw and/or the magnet group 697B and/or thehousing that houses the magnet group 697B.

Continuing with reference to FIG. 14 , method 1400 further includesmethod action 1420, which includes obtaining access to a recipient of amedical device including a magnet group implanted in the recipient.Method 1400 also includes method action 1430, which includes exposingthe recipient and the magnet group to an MRI field of at least 2.5 Twithout removing the magnet group. In a variation of this method, theMRI field is at least 1, 1.5, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4,4.25, 4.5, 4.75 or 5 T or any value or range of values therebetween in0.1 T increments.

Superimposed onto the magnet group 697B of FIG. 6R are dimension valuesD3, D4 and D5. D3, D4, and/or D5 can be individually or collectivelymore than, less than or equal to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8,0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2,2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or more mm or anyvalue or range of values therebetween in 0.01 mm increments (e.g., 1.12mm to 4.44 mm, 3.55 mm, 5.44 mm, etc.). It is noted that theaforementioned values can be applicable to the other shaped magnets,such as the rectangular shape and square shape. In this regard,diameters normal to the distances of FIG. 6R can be less than, greaterthan or equal to 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.5, 4, 4.5, 5, 5.5,6, 7, 8, 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19,or 20, or 21, or 22, or 23, or 24, or 25 or 26 or 27 or 28 or 29 or 30or 31 or 32 or 33 or 34 or 35 or 36 or 37 or 38 or 39 or 40 or more mmor any value or range of values therebetween in 0.01 mm increments.

Consistent with the teachings detailed above, in at least some exemplaryembodiments, the magnet group is configured to spin or otherwise rotatewithin the housing or otherwise relative to the other components of theimplantable device when exposed to a magnetic field. In an exemplaryembodiment, the spinning/rotation can be less than equal to or greaterthan 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130,140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270,280, 290, 300, 310, 320, 330, 340, 350, or 360 degrees or more, or anyvalue or range of values therebetween in 1° increments from theorientation that was present prior to the exposure to the magneticfield. This magnetic field to which the implanted magnet is exposed canbe a magnetic field that is less than, greater than and/or equal to 0.5,0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.75, 2, 2.25, 2.5,2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 9, 10, 11, 12, 13, 14, 15,20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200,225, 250, 275, 300, 350, 400, 450, 500, 550, 600, 700, 800, 900, or 1000times or more (or any value or range of values therebetween in 0.1increments) stronger than the magnetic field generated by theimplantable magnet group or magnet, and/or when exposed to a magneticfield that is less than, equal to and/or greater than 0.25, 0.5, 0.75,1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6 or moreTesla or any value or range of values therebetween in 0.05 increments)as measured at a location 0.5, 0.75, 1, 1.5, or 2 inches away from theimplantable magnet/magnetic group. In an exemplary embodiment, themagnet will spin (or perhaps rotate is a better word, as the magnet willlikely not complete a 360 degree rotation) when exposed to any of thesemagnetic fields, while in other embodiments the magnet will not rotatewhen exposed to any of those fields, while in other embodiments, themagnet will only rotate when exposed to a magnetic field that is thesame as or stronger than one or more of those detailed and will notrotate when exposed to a lower strength field. In an exemplaryembodiment, the bushing and/or the screw 222 can be splined or keyedsuch that it interfaces with the magnet group or the housing enclosingthe magnet so that the magnet group will not rotate. In an alternateembodiment, it is the clamping force between the head of the screw andthe magnet group/housing that houses the magnet group that prevents themagnet group from rotating.

In an exemplary embodiment, the bone fixture can have a spline or a keythat interacts with the magnet group and/or the housing that preventsthe magnet group and/or housing from rotating.

In an exemplary embodiment, the magnet group and/or the housingenclosing the magnet group is configured to resist rotation/not rotatewhen subjected to a torque about the longitudinal axis of the group ofat least 0.1, 0.15, 0.2, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5,2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45 or 50 or 60 or 70 or80 or 90 or 100 or more inch-pounds or any value or range of valuestherebetween in 0.05 inch-pound increments. Thus, as can be seen fromthe above, in an exemplary embodiment, there is an apparatus that isconfigured such that the magnet group resists rotation as a unitrelative to the housing about an axial direction with respect to a firsttorque range applied about the axial direction to the magnet group andenables rotation as a unit relative to the housing about the axialdirection with respect to a second torque range that has components thatare substantially larger than the components of the first torque range.The torque ranges can be any values within the above-noted ranges in0.05 inch-pound increments.

Also, there is an implant that is configured such that the magnetgroup/magnet apparatus/magnet, does not rotate relative to the housingmore than 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2,1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.25, 2.5, 2.75, 3, 3.25, 3.5,3.75, 4, 4.25, 4.5, 4.75, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10,11, 12, 13, 14 or 15 degrees or any value or range of valuestherebetween in 0.01° increments when exposed to a torque about thelongitudinal axis of less than, greater than or equal to 0.1, 0.15, 0.2,0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5,5.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 30, 35, 40, 45 or 50 or 60 or 70 or 80 or 90 or 100 or moreinch-pounds or any value or range of values therebetween in 0.05inch-pound increments.

Thus, as can be seen, in an exemplary embodiment, there is animplantable medical device, comprising a magnet (which can be a magnetportion of a magnet group, or a monolithic magnet disk, etc.) and a bodyencompassing the magnet. In an exemplary embodiment, the implantablemedical device is configured to enable the magnet to rotate. In anexemplary embodiment, this rotation is enabled, with respect to exposureto a magnetic field, only under a magnetic field that is stronger thanat least 1.1, 1.2, 1.3, 1.4, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.5, 4,4.5, 5, 5.5, 6, 6.5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35,40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275, 300,350, 400, 450, 500, 550, 600, 700, 800, 900, or 1000 or more, or anyvalue or range of values in 0.01 increments times the magnetic fieldgenerated by the magnet. In an exemplary embodiment, the body is a caseand the rotation is rotation relative to the case. In an exemplaryembodiment, the case is a titanium case that has a rectangularcross-section that is slightly larger than the magnet that is locatedtherein. An exemplary embodiment, this can be a plastic case such ismade out of PEEK. In an exemplary embodiment, the case can have anonrectangular cross-section and can be any shape that can enableutilitarian teachings detailed herein. In an exemplary embodiment, thereis an apparatus, that includes the implantable medical device and anexternal component including a second magnet, wherein the externalcomponent is held proximate the implantable medical device via magneticattraction between the magnet and the external magnet. In an exemplaryembodiment, the implantable component is configured such that theexternal component can be rotated 90, 180, 270, or 360 degrees relativeto the implantable medical device when the two components are within 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 mm of each other orany value or range of values therebetween without the magnet in theimplantable component rotating relative to the body and/or the remainderof the implantable medical device, the rate of rotation being no morethan 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 degrees persecond. In an exemplary embodiment, the implantable component isconfigured such that the external component can be rotated 90, 180, 270or 360 degrees relative to the implantable medical device when the twocomponents are within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or15 mm of each other with the magnet in the implantable componentrotating relative to the body and/or the remainder of the implantablemedical device no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 degrees,the rate of rotation being no more than 5, 10, 15, 20, 25, 30, 35, 40,45, 50, 55, or 60 degrees per second. In an exemplary embodiment, theimplantable component is configured such that a magnet having a force atleast 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 300,400, or 500 or more, or any value or range of values therebetween ininteger increments of the implanted magnet can be rotated 90, 180, 270,or 360 degrees relative to the implantable medical device when the twocomponents are within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or15 mm of each other or any value or range of values therebetween withoutthe magnet in the implantable component rotating relative to the bodyand/or the remainder of the implantable medical device, the rate ofrotation being no more than 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55,or 60 degrees per second. In an exemplary embodiment, the implantablecomponent is configured such that the aforementioned magnet can berotated 90, 180, 270, or 360 degrees relative to the implantable medicaldevice when the two components are within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, or 15 mm of each other with the magnet in theimplantable component rotating relative to the body and/or the remainderof the implantable medical device no more than 1, 2, 3, 4, 5, 6, 7, 8,9, or 10 degrees, the rate of rotation being no more than 5, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, or 60 degrees per second. It is noted thatin some embodiments, the aforementioned magnet is generating a magneticfield that is aligned and results in a pulling force, including amaximum pulling force, towards the implantable magnet.

It is noted that in some embodiments, any of the above can alsocorrespond to the features of the magnet of the external device.

In some embodiments, the implantable medical device and/or the externalmedical device is configured to enable the respective magnet to rotateonly under very strong external magnetic fields.

In an exemplary embodiment, there is an implantable medical device,wherein the body is an enclosure that at least partially encloses themagnet. Also, designed friction between the body and/or a componentwithin the body and the magnet prevents the magnet from rotating under amagnetic field that is not as strong as the magnetic field that causesthe magnet to rotate. In an exemplary embodiment, pressure force exertedby the body directly and/or indirectly onto the magnet prevents themagnet from rotating under a magnetic field that is not as strong as themagnetic field that causes the magnet to rotate. By designed friction,it is meant friction that is clearly purposely imparted to increase thetorque needed to begin rotation, as opposed to friction that existssimply because there is friction in everything.

FIG. 20B presents an exemplary embodiment of a magnet apparatus 2001that includes a magnet 2010 (which can be instead a magnet group—more onthis below) located in a housing 2020 that hermetically isolates theinterior of the housing from the outside environment. In an exemplaryembodiment, a viscous substance 2035, such as a viscous fluid, islocated inside the housing, and otherwise, in combination with themagnet, fills the interior of the housing or otherwise substantiallyfills are effectively fills the interior of the housing. In an exemplaryembodiment, results in a design friction that is higher than that whichwould otherwise be the case. This enables the magnet 2010 to rotatewithin the housing with more difficulty. In an exemplary embodiment, themagnet 2010 can instead be a magnet group or magnet apparatus accordingto any of the teachings detailed herein. Again, in an exemplaryembodiment, such as where there are three separate components, themagnet group can be encased in a second housing (not shown) or in amembrane or in a sealed environment to isolate the magnet componentsfrom the fluid inside the housing. Note also that in some embodiments,the extra-membrane or the sealing or the extra housing can also beutilized with the monolithic magnet as well.

In an exemplary embodiment, the substance 2035 can be a gel. In anexemplary embodiment, the substance 2035 can be a particulate matter,such as sand or a powder or a grit material that is “packed” into thespaces between the magnet in the housing (or the housing, for example,that houses the magnet inside the housing 2020) that otherwise increasesthe design friction and thus makes it more difficult for the magnet 2010(or magnet group or magnet apparatus), with or without the additionalhousing, to rotate within the housing 2035.

FIG. 21 presents an alternative exemplary embodiment of the magnetapparatus where the magnet 2010 is resting on the bottom of the housing2020. The embodiment of FIG. 21 can be utilized with a lubricant 2030and/or a viscous substance 2035 or any other substance that can increasethe friction between the two components. In an exemplary embodiment, thebottom surface of the housing can be a low friction surfaces while inother embodiments the bottom surface of the housing can be a highfriction surface in an exemplary embodiment, the housing can press downupon the magnet to push the magnet down onto the bottom surface of thehousing (the housing can be bowed downward, or can have a portion thatextends down to the magnet). Alternatively, and/or in addition to this,a component can be located between the magnet and the housing thatapplies the force on to the magnet to push the magnet onto the bottomsurface. In an exemplary embodiment, this component can be held in placeby the magnet and/or by the housing. In an exemplary embodiment, it canbe attached to one or both.

That said, in an exemplary embodiment, the position of the magnet issimply that which results from gravity or the like or otherwise as aresult of meniscus forces.

FIG. 22 presents an exemplary embodiment that utilizes a bearing 2040 toenable rotation of the magnet 2010 in the housing 2020. In an exemplaryvariation of the embodiment of FIG. 22 , a substance 2035 can be locatedin the housing, which substance increases the friction and otherwiseresist rotation of the magnet 2010 in the housing 2020. Thus, byutilizing the bearing 2040 so that the magnet can rotate easily relativeto the housing, the combination of the substance 2035 and the bearingpermits the rotational features of the magnet relative to the housing tobe controlled in a more defined manner relative to that which wouldotherwise be the case in the absence of the bearing 2040. Of course, inembodiments where it is desired to have low friction and thus enable themagnet to relatively rotate freely, the bearing itself can be utilized.The bearing can be a ball bearing or an oilite bearing (body impregnatedwith a lubricating substance) or can be a roller bearing, etc. Anybearing that can enable the magnet to rotate relatively easily can beutilized at least some exemplary embodiments. FIG. 23 presents analternate exemplary embodiment utilizing a support structure 2045. Thesupport structure is a high friction material and thus resists movementof the magnet 2010 relative to the housing 2020. In an exemplaryembodiment, structure 2045 can be a rubber disk, rubber block, etc.Indeed, in some embodiments, structure 2045 can be a frangible body thatbreaks upon the application of a given torque indeed, in an exemplaryembodiment, structure 2045 can be a clutch like mechanism that preventsrotation of the magnet relative to the housing up until a certain torqueis applied, and then permits the rotation.

FIG. 24 presents an exemplary embodiment where there is no viscous orlubricant substance in the housing, and the only components other thangas located in the housing that create the link between the magnet 2010and the housing 2020 is the bearing 2040, or the movement resistingstructure 2045. In an exemplary embodiment, structure 2045 can be agooey substance that permits some rotation of the magnet 2010 relativeto the housing 2020 (e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10degrees, for example), when subjected to a torque/torque within a givenrange, and then permits more rotation (more than 10, 20, 30, 40, 50degrees or more) when that torque is exceeded. By way of example, thiscan enable a little bit of give (rotation) for low torques, and thentotal rotation for the larger torques.

FIG. 25 presents an alternate exemplary embodiment of the magnetapparatus 2004, which utilizes fiction components 2050. In an exemplaryembodiment, friction component 2050 is interference fitted between theouter circumference that rotates at the highest velocity of the magnet2010 and the housing wall. Depending on the surface area of thiscomponent and/or the amount of friction fit (where the magnet 2010 isradially held in place so that the friction component 25 zero does notsimply push the magnet to the side), a desired torque resistance regimecan be achieved. In an exemplary embodiment, the friction component 2050can be a cylindrical rod that can be fixed to the magnet and/or thehousing by way of adhesive, welding, or a divot/detent in one of thehousing of the magnet (or both—in an alternate embodiment, thedivot/detent can be such that it requires a certain torque to be appliedbefore the cylinder “pops out” of the divot/detent). In an exemplaryembodiment the friction components 2050 can be arcuate bodies that arecontrary to the inner surface of the housing and the outer surface ofthe magnet 2010 over a certain percentage of the overall 360° of theinterior of the housing (like a drum brake assembly), the greater theextension in the axial and/or radial direction, the greater the frictionand thus the higher torque that is required to commence rotation. In anexemplary embodiment, the friction component can be an asbestoscomponent and/or can be a component that is the same as a brake pad inan automobile (this can also be the case with respect to the component2045 detailed above). The friction component 2050 can be a rectangularcross-section beam that is interference fitted between the housing andthe magnet. In an exemplary embodiment, a plurality of frictioncomponent 2050 can be interference fitted between the magnet and thehousing.

FIG. 26 presents an alternate exemplary embodiment where a longerfriction component 2052 is located between the housing and the magnet2010. Because the component is longer than that of the embodiment ofFIG. 25 , there will be more friction surface between the twocomponents, and thus a larger torque will be required to commencerotation relative to that of FIG. 25 . The embodiment of FIG. 27presents yet alternate exemplary embodiment where there are two frictioncomponents 2050 and 2054 that are shown. Here, the lengths and thepositions can be varied to vary the amount of torque that is required tocommence rotation of the magnet. Any arrangement of section componentsthat can enable the teachings detailed herein can be utilized at leastsome exemplary embodiments.

FIG. 28 depicts an isometric view of an exemplary embodiment of a magnetapparatus according to any of the embodiments above in a housing 2021,with the top of the housing removed/not shown, for clarity, where thehousing 2021 can be any of the housing detailed herein and/or variationsthereof.

In an exemplary embodiment, the magnet apparatuses located in thehousing are configured, or, more accurately, the assembly is configuredto enable the magnet apparatus inside the housing to rotate relative tothe housing about the longitudinal axis of the apparatus/about an axisthat is normal to the skin of the recipient when implanted therein. Thatsaid, in an alternate embodiment, the magnet apparatuses located in thehousing, or, more accurately, the assembly is configured to prevent themagnet apparatus inside the housing from rotating relative to thehousing about the longitudinal axis. In some embodiments, the assemblyis configured to prevent the magnet apparatus inside the housing fromrotating relative to the housing about the longitudinal axis for certaintorques, but above a certain level or when exposed to other torques, themagnet apparatus can rotate relative to the housing (at least if thehousing is held fixed or otherwise there is something that can resistrotation of the housing, such as, for example, the interaction of thesilicone body of the implant with the outside of the housing).

In some exemplary embodiments, there is metal on metal contact betweenthe magnet portion(s) and the housing. In an exemplary embodiment, acoating and/or a lubricant is provided so as to reduce the frictionbetween the two components. In an exemplary embodiment, the magnetapparatuses can be interference fitted into the housing so as to createan assembly where the magnet apparatus will not rotate relative to thehousing. In an exemplary embodiment, the magnet apparatuses can beinterference fitted in the housing so as to create an assembly where themagnet apparatus will only rotate relative to the housing if asufficient torque is applied. In an exemplary embodiment, the magnetapparatuses can be slipped fitted into the housing so as to create anassembly where the magnet apparatus will rotate relative to the housing,where, in some embodiments, only if a sufficient torque is applied,while in other embodiments, even if a relatively de minimis torque isapplied that simply provides sufficient inertia to get the magnetapparatus to rotate (analogous to the minimum forces needed to have acar wheel rotate—it is designed to rotate, and, in fact, is designed tobe as low friction as possible, but there is still a relatively deminimis amount of force that is needed to get the wheel to rotate).

In an exemplary embodiment, the maximum outer diameter of the magnetapparatus is less than the minimum inner diameter of the housingchamber. In an exemplary embodiment, this configuration can enable themagnet apparatus to rotate relative to the housing.

In an exemplary embodiment, the maximum outer diameter of the magnetapparatus can be Z % of the minimum diameter of the chamber of thehousing in which the magnet apparatus is located, in a plane normal tothe longitudinal axis of the apparatus, where Z can be 90, 91, 92, 93,94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108,109, 110, or any value or range of values therebetween in 0.01increments.

FIG. 29 presents an exemplary embodiment that utilizes a racetrackshaped housing that houses only the central portion. Here, the racetrackshaped central portion 656 a or otherwise any utilitarianly shapedcentral portion (the central portion can be a bar shaped element—this isalso the case with the embodiments above) can be placed into a hermetichousing 2022 that is in the shape of a racetrack (cross-section). Thefit can be interference, slip or clearance, and an adhesive and/or afiller material can be located between the central portion and the wallsof the housing, if such is utilitarian, such as to prevent the centralportion from rattling or otherwise moving relative to the housing 2022(other embodiments that provide anti-rattling are described below).Then, with respect to FIG. 30 , the racetrack shaped housing 2022 iscombined with the flanking portions 636 b, and then is placed into ahousing 2023, which can be plastic, metal, etc., and may or may not behermetically sealed. Any of the connection techniques between theflanking portions and the central portion detailed herein can beutilized in at least some exemplary embodiments. While the racetrackshaped housing is disclosed, in an exemplary embodiment, any shapehousing that can have utilitarian value can be utilized in at least someexemplary embodiments. In an exemplary embodiment, the embodiments ofFIGS. 29 and 30 reduce the metal footprint inside the coil (e.g., whereimplemented in a cochlear implant, or an active transcutaneous boneconduction device) to reduce the impact on the RF link. In an exemplaryembodiment, the strength of the RF link is at least 5, 10, 15, 20, 25,30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120,130, 140, 150, 160, 170, 180, 190, 200, 225, 250, 275, 300, 350, 400,450, or 500% in the absence of these teachings, all other things beingequal. The housing can be metallic or can be on the other material thatcan have utilitarian value. The hermetic housing can be metallic, andthe housing that is utilized to encase the sub-assembly with the moonscan be non-metallic.

FIG. 31 presents an exemplary embodiment that utilizes moon-shapedhousings that respectively houses only the flanking portions. Here, themoon shaped flanking portions 656 b otherwise any utilitarianly shapedcentral portions can be placed into a hermetic housing 2024 that is inthe shape of half-moon (cross-section). The fit can be interference,slip or clearance, and an adhesive and/or a filler material can belocated between the flanking portion and the walls of the housing, ifsuch is utilitarian, such as to prevent the central portion fromrattling or otherwise moving relative to the housing 2024. Then, withrespect to FIG. 32 , the racetrack shaped housing 2024 is combined withthe central portion 656 a, and then is placed into a housing 2023, whichcan be plastic, metal, etc., and may or may not be hermetically sealed.Any of the connection techniques between the flanking portions and thecentral portion detailed herein can be utilized in at least someexemplary embodiments. While the moon-shaped housings are disclosed, inan exemplary embodiment, any shape housing that can have utilitarianvalue can be utilized in at least some exemplary embodiments. In anexemplary embodiment, the embodiments of FIGS. 31 and 32 reduce themetal footprint inside the coil.

In an exemplary embodiment, the techniques of the embodiment of FIGS. 29and 30 can be combined with those of FIGS. 31 and 32 , consistent withthe fact that any embodiment feature can be combined with any otherembodiment feature unless otherwise specifically noted or otherwise notenabled by the art.

FIG. 33 depicts an exemplary embodiment of an anti-rattlingimplementation that utilizes the above exemplary embodiments where thecentral portion and/or the flanking portions is/are made of anonmagnetic indoor nonmetallic material. In this exemplary embodiment,flanking portions 636 b extended outwards and outwards beyond thecentral portion 636 a, as seen. In this exemplary embodiment, thecentral portion can be a magnetic material, such as a magnet, and theflanking portions can be the polymer-based material or nonmagneticmaterials, etc., according to the teachings detailed herein and/orvariations thereof. In this exemplary embodiment, the flanking portions636B are interference fitted into the housing 2020, while in otherembodiments, the flanking portions 636B are slipped fitted. In anyevent, the tolerances are such that the magnet apparatus that is locatedin the housing 2020 will not rattle or otherwise rattle less than thatwhich would otherwise be the case in the absence of the teachingsdetailed herein. In an exemplary embodiment, a measured noise resultingfrom a given vibratory regime is reduced by at least 0.1, 0.2, 0.3, 0.4,0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, 3,3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 9, or 10 dB or more, or any value orrange of values therebetween in 0.01 dB increments relative to thatwhich be the case if the entire component was made of metalliccomponents/magnetic components. (It is noted that in at least some otherexemplary embodiments detailed herein, these performance features arealso present.)

FIG. 34 presents an alternate exemplary embodiment where the flankingportions 636 b are non-magnetic/nonmetallic, and the lateral sides arespaced away from the side walls of the housing 2020, as can be seen. Inthis exemplary embodiment, the flanking portions 636 b are interferencefitted into the housing 2020 in the longitudinal direction and/orslipped fitted in that longitudinal direction. In this embodiment, thecenter portion 636 a is a permanent magnet, and the flanking portionsare made of a nonmagnetic material according the teachings herein.

FIG. 35 presents an alternate exemplary embodiment, where the flankingportions 636 b are nonmagnetic/nonmetallic, and the lateral sides arespaced away from the top walls and bottom walls of the housing 2020, ascan be seen. In this exemplary embodiment, the flanking portions 636 bare interference fitted into the housing 2020 in the lateral directionand/or slipped fitted in that lateral direction. In this embodiment, thecentral portion 636 a is a permanent magnet, and the flanking portionsare made of a nonmagnetic material according to the teachings herein.

FIG. 36 presents yet an alternate exemplary embodiment, where instead ofthe flanking portions being utilized to support the central portion awayfrom the housing 2020 such that the housing does not contact the centralportion/the central portion does not contact the housing, here, thecentral portion 636 a is in contact with the housing 2020, and theflanking portions 636 b also contact the housing 2020 and the lateraldirection. Thus, the two separate components collectively provide thepreventive movement in two directions.

FIG. 37 presents yet another exemplary embodiment, where instead of theflanking portions being utilized to support the central portion awayfrom the housing 2020 such that the housing does not contact the centralportion/the central portion does not contact the housing, here, thecentral portion 636 a is in contact with the housing 2020, but theflanking portions 636 b are spaced away from the walls of the housing2020. In this exemplary embodiment, as in the embodiment of FIG. 36 ,the central portion 636 a can be interference fitted and/or slippedfitted into the housing 2020.

In at least some exemplary embodiments, the embodiments described abovereduce and/or prevents and/or eliminate the aforementioned rattlingaccording to any of the aforementioned performance regimes. In anexemplary embodiment, this can have utilitarian value with respect toscenarios where the recipient undergoes an MRI scan and/or during normaluse of the implant that might cause rattling, and the teachings detailedherein reduce and/or eliminate that rattling.

In some embodiments, the flanking portions and/or the central portionsare arranged relative to the housing 2020 such that the magnet apparatuscan rotate, while in other embodiments, those components are arrangedsuch that the magnet apparatus cannot rotate within the housing, whilein other embodiments, consistent with the teachings detailed herein,these components are arranged such that the magnet apparatus can rotatewithin the housing only after a given torque is imparted onto the magnetapparatus relative to the housing. Some additional details of this willbe described in greater detail below. First however, some embodimentswill be described with respect to the rotating magnet apparatus which isa single magnet.

FIG. 38 depicts another exemplary embodiment of an apparatus 2008. Here,there is a large cutout within the magnet 2012. A cylindrical body 2060is located in the cutout. FIG. 39 presents a cross-section through theembodiment of FIG. 38 in a direction perpendicular to the plane shown inFIG. 38 . In this exemplary embodiment, the cylindrical body 2060 doesnot extend the full height of the magnet, while in other embodiments, itcan extend the full height of the magnet. In an exemplary embodiment,the cylindrical body 2060 can be a rubber body (as can be the frictioncomponents of the embodiments above) that is interference fitted betweenthe housing wall and the magnet 2012. In an exemplary embodiment, thebody can be a metallic body or a plastic body (as can be any of thefriction components detailed herein). Any arrangement that can preventthe magnet from rotating until a certain torque is applied thereto canbe utilized at least some exemplary embodiments.

FIG. 40 presents yet another exemplary embodiment of a magnet apparatusthat includes a housing 2022 and a magnet 2010. In this exemplaryembodiment, the housing walls are rough surface walls that impart higherfriction than that which would be the case if a smoother wall wasutilized. In an exemplary embodiment, the location/distance of extensionof the roughened surface can be varied to vary the friction forces. Inan exemplary embodiment, the roughened surface can extend completelyacross from one side to the other on both sides, whereas in anotherexemplary embodiment, the roughened surface only exist on one side, ascan be seen in FIG. 41 . In an exemplary embodiment, the roughenedsurface can be limited to the locations only at the geometric center ofthe housing while in other embodiments, the roughened surfaces can belimited to locations only at the outboard locations. Combinations of thetwo can be utilized. It is to be understood that the further out thatthe roughened surfaces are from the geometric center, the more frictionforce will be generated for a given surface area, all other things beingequal. By varying the positions, the torque that is required to initiaterotation can be varied.

FIG. 42 presents another exemplary embodiment where ball bearings arelocated in detents in the housing 2024 and/or in the magnet 2010/2011.In an exemplary embodiment, these ball bearings can be rubber and can becompressed to vary the amount of torque that is required to beginrotation of the magnet. In an exemplary embodiment, the bearings can bemetal or can be plastic, etc. That said, in an exemplary embodiment, thebearings can be low friction components that actually enhance rotation.In this regard, in an exemplary embodiment, the bearings could belocated therein in a manner where the bearings are not substantiallycompressed, as opposed to the other embodiments where the bearings arecompressed or otherwise there is a relatively large downwardforce/pressure between the two components to increase the friction andthus increase the amount of torque that is required to begin rotation.

In some embodiments, there is a disk shaped, diametrically polarizedimplant magnet (in other embodiments, it is a combination polarizedmagnet, such as in FIG. 4A) enclosed in a case/shell/cassette. Amechanism is located inside the housing/cassette to sufficiently securethe magnet so that it shall remain fixed during normal operation, suchas when paired with the external sound processor magnet or similarly lowstrength magnetic fields. Conversely, under the influence of a highstrength magnetic field (such as an Mill field, the mechanism will allowthe implant magnet to reorient itself to align with the field, reducingthe experienced torque and ensuing pain/damage. The orientation willremain until exposed to another high strength field. The viscoussubstance/friction enhancing substances within the cassette can coat themagnet and/or the inside of the housing and/or the intentionallyroughened internal surfaces (relative to the normal surface/that whichexists from manufacturing without roughening) can be located on any ofthe components.

Further, a convex cassette interior can result in specific points ofcontact with the magnet in the housing can increase the torque requiredto begin rotation of the magnet. By way of example only and not by waylimitation, FIG. 43 depicts an exemplary housing 2025 that houses magnet2010. As seen, the interior side walls of the housing 2025 are convexlyshaped inside so as to compress against the magnet 2010. FIG. 44presents an alternate embodiment of a housing 2026 where the top andbottom walls include convex portions 2037 that compress upon the magnet2010. These configurations increase the torque that is required to beginrotation of the magnet relative to that which would otherwise be thecase in the absence of these components.

It is noted that while the embodiments shown in FIGS. 43 and 44 depictthe outer surfaces of the walls of the housing as being flat orotherwise parallel to each other, in an alternate embodiment, the wallscan be bow shaped so that the walls extend in towards the magnetapparatus forming a convex shape on the inside in a concave shape on theoutside. Indeed, in an exemplary embodiment, the case/housing can bedeformed utilizing a press or the like with the magnet insider prior tothe magnet being placed inside, and then the lid can be forced onto therest of the housing such that the lid must deformed to fully close thelid, and the resulting interference causes the force that resists themagnet from rotating until a certain torque is achieved.

In view of the above, it can be seen that in at least some exemplaryembodiments include a magnet and housing combination that does notgenerate heat due to kinetic energy associated with one of the partsmoving relative to the other. Thus, in an exemplary embodiment, there isthe action of attaching and detaching an external component to arecipient's head at a location above implanted component that has themagnet apparatus as detailed herein or variations thereof wherein theaction of attaching does not result in heat generation. Still further,in at least some exemplary embodiments, there are exemplary methodswhere the recipient does not have an external component attached tohimself or herself but where the implantable component includes themagnet apparatuses as detailed herein at least in some embodiments orvariations thereof, and the period of time where there is no externalcomponent that is attached at least for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 hours at a time or any value orrange of values therebetween in 0.1 hour increments but where theinternal magnet does not move or otherwise rotate relative to thehousing. Thus, there is no heat generation or effectively no heatgeneration as a result of kinetic energy associated with the magnetrelative to the housing for at least any of the aforementioned periodsof time.

Further, at least some exemplary embodiments according to the teachingsdetailed herein that utilize the compression features or the higherfriction features can also result in the prevention of unintentional orundesirable vibrational rattling of the magnet within the housing, suchas that which can occur when the external component is not paired withthe implantable component or otherwise when there is no external magnetthat is generating a field that interacts with the implanted magnet.Accordingly, in an exemplary embodiment, there are exemplary methodswhere the recipient does not have an external component attached tohimself or herself but where the implantable component includes themagnet apparatuses as detailed herein at least in some embodiments orvariations thereof, and the period of time where there is no externalcomponent that is attached at least for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 hours at a time or any valueor range of values therebetween in 0.1 hour increments but where theinternal magnet does not move or otherwise rotate relative to thehousing. Thus, there is no noise or energy or effectively no noise orenergy generated by the implanted magnet for at least any of theaforementioned periods of time.

In an exemplary embodiment, this can have utilitarian value with respectto avoiding rattling or otherwise noise or tactical sensation resultingfrom a moving component within a body of the recipient.

In an exemplary embodiment, there is an implantable (or external)medical device, wherein the body is an enclosure that at least partiallyencloses the magnet, and a pressure force exerted by the body directlyand/or indirectly onto the magnet prevents the magnet from rotatingunder a magnetic field that is not as strong as the magnetic field thatcauses the magnet to rotate. In an exemplary embodiment, a force of 0.1,0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5,1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.5, 5, 5.5, 6, 6.5, 7,7.5, 8, 8.5, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25 or more pounds of force are applied onto the magnet.

In an exemplary embodiment, the body is an enclosure that at leastpartially encloses the magnet (e.g., a housing as disclosed above). Asseen, in some embodiments, high friction element(s) between and/or partof the body directly and/or indirectly in contact with the magnetprevent(s) the magnet from rotating under a magnetic field that is notas strong as the magnetic field that causes the magnet to rotate. In anexemplary embodiment, the external component including a second magnetand the second magnet is rotatable within the external component (alongwith or instead of the magnet in the implantable component). In anexemplary embodiment, the external component includes a second magnetand the second magnet is rotatable within the external component (inaddition to or instead of the magnet in the implant). Further, theexternal component is configured to enable the second magnet to rotateunder the magnetic field generated by the magnet in the implant when theexternal component is held proximate the implantable medical device. Itis noted that in some embodiments, the external component has anidentical magnet apparatus as the implant, and in other embodiments, itis different from that of the implant. Any disclosure herein of animplanted magnet/magnet apparatus/magnet group corresponds to adisclosure of an external device that has such, and vice versa.

By does not rotate, it is meant that the magnet group only moves anamount that would be consistent with deformation/flexure of thecomponents of the system when a force is applied (by analogy, a cinderblock will compress when a force is applied, but the block does not movein any meaningful way). That said, in some embodiments, theaforementioned features can be classified in terms of a magnet groupthat does not rotate more than 2, 3, 4, 5, 6, 7, 8 9 or 10 degrees fromits initial orientation.

It is noted that while teachings detailed above have been directedtowards a magnet group that has magnet portions with different axes ofmagnetic flux, in an alternate embodiment, the teachings detailed hereincan be applicable to a magnet apparatus where all of the flux axes arealigned the same (diametrically, radially, obliquely, etc.).Accordingly, any disclosure herein to a magnet group corresponds to adisclosure of an alternate embodiment where the magnet group is a magnet(or a group) that has a single magnetic flux and/or the generatedmagnetic flux of the various components are all aligned or otherwisesubstantially aligned with each other.

In the embodiments described above, it is a screw thread that ultimatelyprovides the resistance against the rotation (whether it be the screwthread of the screw that fits into the bone fixture, or the screw threadof the bone fixture that interfaces with the bone—actually, acombination of the two can be also the case). Accordingly, in anexemplary embodiment, the threat alignment can be adopted such that anytorque that is likely to be experienced owing to the exposure ofmagnetic field result in a tightening effect (analogous to the directionof threads of wheel lugs—the thread (right hand vs. left hand) isselected based on the rotation of the wheels so that the rotationtightens the lug nuts). In this regard, the torque applied to the magnetgroup that results from the exposure of the magnetic field istransferred into the screw in a manner that actually further tightensthe screw.

The above performance features associated with the rotations andnon-rotations and resistance to rotation until a certain torque isachieved of the magnet/magnet group/magnet apparatus can also beapplicable to the embodiments detailed above where a non-magneticmaterial/nonmetallic material is utilized to support the magnet portionsof the magnet apparatus and/or or otherwise included in the magnetapparatus (the nonmagnetic portions need not necessarily be utilized forsupport—in other embodiments, these are simply utilized to center atleast partially the magnet apparatus—in this regard, while someembodiments are directed towards anti-rattling/limited rattlingembodiments, other embodiments are not necessarily so directed). In thisregard, in an exemplary embodiment, the embodiments that utilize, forexample, flanking components made of a polymer or a nonmagnetic materialor a non-metallic material can, in some embodiments, be utilized so thatthere is a modicum of resistance to rotation until a certain torque isachieved. In some embodiments, the flanking components guide the magnetcomponent with respect to rotation within the housing. That said, inalternative embodiments, such as where the flanking portions of themagnetic materials, in some embodiments, the central portion is thecomponent that guides the flanking portions within the housing duringrotation.

In the embodiments where the magnet is made of a discorectangle orracetrack configuration, and is shaped magnetized along its length, suchcan be utilized in combination with the flanking portions, in someembodiments, to enable the magnet to rotate within the disk-shapedhousings detailed herein. Further, as noted above, the discorectangularconfiguration of the magnet can be housed in a discorectangular shapedhousing which rotates within a non-conducting housing, made of PEEK orPTFE, etc. In the embodiments where the magnet is made of half-moonshapes and the magnets are magnetized along their length, such can beutilized in combination with the central portion, in some embodiments,to enable the magnets to rotate within the disk-shaped housings detailedherein. Further, as noted above, the moon shaped magnets can be housedin a moon shaped housing which rotates within a non-conducting housing,made of PEEK or PTFE, etc. In an exemplary embodiment, the outer housingcan be made of a metallic material as well.

In at least some embodiments, the flanking portions and/or the centralportion is made of low friction material such as PTFE or PEEK, while inother embodiments, the flanking portions under the central portion ismade of high friction material. In an exemplary embodiment, as will beunderstood, some embodiments will provide for much freer rotationrelative to that which would otherwise be the case, all other thingsbeing equal, while in other exemplary embodiments, as will beunderstood, some other embodiments provide for much less/more restrictedrotation relative to that which would otherwise be the case all otherthings being equal.

In an exemplary embodiment, a torque of 0.01, 0.02, 0.03, 0.04, 0.05,0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17,0.18, 0.19, 0.20, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7,0.8, 0.9, 1.0, 1.2, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75,4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33,34, 35, 36, 37, 38, 39, 40, 45, 50, 60, 70, 80, 90, or 100 or moreinch-pounds, or any value or range of values therebetween in 0.005inch-pound increments, will cause the magnet apparatus within thehousing to rotate relative to the housing. That said, in an exemplaryembodiment, the application of any one or more the aforementionedtorques will cause the magnet apparatus to break. In an exemplaryembodiment, the application of any one or more the aforementionedtorques will still not cause the magnet apparatus to rotate relative tothe housing.

In an exemplary embodiment, the magnet apparatus can move, relative tothe interior of the housing, no more than or more than 0.001, 0.002,0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04,0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16,0.17, 0.18, 0.19, 0.20, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6,0.65, 0.7, 0.8, 0.9, or 1.0 millimeters or any value or range of valuestherebetween in 0.001 mm increments in one or two or three directions ofthe Cartesian coordinate system with one axis aligned with thelongitudinal axis of the magnet apparatus, at least without effectivelydeforming the housing/relative to an ideally perfectly rigid housing. Inan exemplary embodiment, the largest diameter of the magnet apparatusand/or of any of the components of the magnet apparatus is/are no morethan or more than 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 mm or any value orrange of values therebetween in 0.001 mm increments. In an exemplaryembodiment, the largest diameter of the interior cavity of the housingcan be larger than or less than or equal to 4, 5, 6, 7, 8, 9, 10, 11,12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,or 30 mm, or any value or range of values therebetween in 0.001 mmincrements.

In an exemplary embodiment, the racetrack shaped central portions haveflat sides, as opposed to curved sides. That said, in an alternateembodiment, the central portions can have a body that has differentradiuses of curvature about the periphery, such as, for example, insteadof having flat sides as shown in the figures above, the sides arecurved, just with a lower radius of curvature than that of the ends ofthe central portion. In an exemplary embodiment, the ratio of the radiusof curvature of the ends of the central portion to the sides of thecentral portion is 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2,2.25, 2.5, 2.75, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25,30, 35, 40, 45, 50, 60, 70, 80, 90, or 100 or more, or any value orrange of values therebetween in 0.1 increments. In an exemplaryembodiment, the radius of curvature of the ends of the central portioncan be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,or 20 mm, or any value or range of values therebetween in 0.001 mmincrements. In an exemplary embodiment, the radius of curvature of theflanking portions can also be any of these values just detailed.

In an exemplary embodiment, the distance from one side of the centerportion of the other side of the center portion and/or the distance fromone side of the flanking portion to the other side of the flankingportion (from the curved side to the flat side (maximum distance) can be1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20mm, or any value or range of values therebetween in 0.001 mm increments.

While the embodiments detailed herein have frequently been described interms of components that have smoothly curved surfaces, in otherembodiments, faceted surfaces can be utilized that can approximate acurved surface. By way of example only and not by way of limitation, anyone or more of the curves detailed herein can be replaced by 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 flat surfacesthat are contiguous with one another, save for, potentially, edgedbroken surfaces which could be curved or chamfered surfaces between thetwo.

In an exemplary embodiment, the thickness of any of the components ofthe magnet apparatus can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8,1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.25, 3.5, 3.75or 4 mm or any value or range of values therebetween in 0.001 mmincrements. In an exemplary embodiment, the height of the cavity of thehousing can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1,2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.25, 3.5, 3.75 or 4 mm orany value or range of values therebetween in 0.001 mm increments.

In an exemplary embodiment, the portions of the magnet apparatus areflat on the top and the bottom and are parallel to one another, while inother embodiments, as will be described in greater detail herein, theportions on the top and bottom are not necessarily flat and/or notnecessarily parallel to one another.

FIGS. 45, 46, and 47 present alternate embodiments of some componentsthat can be utilized with some embodiments herein. These can be magnetcomponents or non-magnet components. The components can be monolithic,as is the case with all of the components herein in some embodiments, orcan be made up of separate sub-components. In an exemplary embodiment,any apparatus or component herein can be a monolithic apparatus orcomponent unless otherwise proscribed or unless the art does not enablesuch.

As can be seen, one embodiment is a cross-shape, the other is a “battleaxe” shape. The component's if magnets, can have a diametric polarity oran axial polarity (e.g., in and out of the page with respect to the viewof FIG. 103 ). Thus, for example, the north pole of the magnet is at oneblade of the ‘battle axe’, and the south pole of the magnet is at theother end of the ‘battle axe,’ with respect to the diametrically opposedpolarity.

In FIG. 45 , component 10155 can be a magnet. In an exemplaryembodiment, the relief areas 10166 between the arms of the cross providefor the aforementioned rotational features detailed herein and/oranti-rotational features detailed herein. In this regard, in anexemplary embodiment, the relief areas reduce the surface thatinterfaces with the interior surface of the housing, and thus reducesthe friction forces, thus making it easier for the component to rotate.In an alternate embodiment, the arms of the cross can be such that theydeform the housing ever so slightly in a manner that effectively locksthe component 10155 within the housing and thus effectively prevents thecomponent from rotating or otherwise makes it more difficult for thecomponent to rotate.

In an exemplary embodiment, the relief areas 10166 between the arms ofthe cross can be filled with a material that is of a low frictionmaterial, while in other embodiments, the relief areas can be filledwith a material that is a high friction material, these materials caninteract with the inside surfaces of the housing to make rotation easierand/or harder. In an exemplary embodiment, quarter pie shaped components10177, as seen in FIG. 48 , can be located within each of the reliefareas, where the curved area of the pie shaped portions has a largeroverall outer diameter than the arms of the cross of the component10155. (These can correspond to the low friction or high frictionmaterials.) In this regard, these pie shaped components can serve thefunction of the flanking portion detailed above than the otherembodiments. Various shapes can be utilized or otherwise implemented,such as seen in FIG. 49 , where the outer diameter of the component10155 is the same as that of FIG. 104 , but there is more of the 10155than in FIG. 48 .

FIG. 46 and FIG. 47 and FIG. 50 depict the aforementioned battle axeconfiguration. In this exemplary embodiment, as with the crossembodiment, low friction or high friction materials can be located inthe recesses 10166. In an exemplary embodiment, truncated half-moons10177 can be located in the recesses 10166, where the outer curvedsurface extends past the outer surfaces of the component 10155 as seen.

With respect to the dimensions of FIG. 47 , A can be 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,28, 29, or 30 mm or any value or range of values therebetween in 0.001mm increments, B can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15 mm or any value or range of values therebetween in 0.001 mmincrements, C can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 mm or anyvalue or range of values therebetween in 0.001 mm increments, D can be0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8 mmor any value or range of values therebetween in 0.001 mm increments andE can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6,7, 8 mm or any value or range of values therebetween in 0.001 mmincrements.

The embodiments of FIGS. 45-50 can have any of the dimensions detailedherein if those dimensions are applicable (e.g., radius of curvature,maximum diameter, thickness, etc.).

(The embodiment of FIG. 45 is labeled with magnetic pole markings. Thisis related to another embodiment which is described above with theangled pole. Briefly, in an embodiment, the polarity of the magnetcomponents, for such embodiments where the components are magnets, arealigned longitudinally and/or diametrically, while in other embodiments,the polarity is different, as described herein.)

It is noted that components 10177 can be used to support the component10155 or otherwise guide the component in a manner analogous to/the sameway as the teachings above with respect to the flanking components.Thus, the anti-rattling features as well as the torque/rotation featurescan exists in these embodiments as well.

It is further noted that component 10155 can exist in other shapes thandetailed above (as is the case with respect to the central portion ofthe magnet apparatus detailed above and the flanking portions detailedabove). Indeed, the embodiment of FIG. 45 can instead be a circle wherethere are three recesses equally spaced about the periphery at120-degree increments where support components of the like are locatedin those recesses. Alternatively, and/or in addition to this, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15 or more recesses can be located about aperiphery of a component. In this regard, FIG. 51 presents anotherexemplary embodiment where there is a magnet component that includes 6recesses, but can instead be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15 or more recesses arrayed about the perimeter in a symmetrical manner,while in other embodiments these need not necessarily be symmetric. Inthis exemplary embodiment, cylindrical rollers are located in therecesses, which are sized and dimensioned so that the interfaces betweenthe rollers and the component and the interfaces between the rollers andthe sidewall of the housing controls the torque needed to have thecomponent rotate. Particularly, component 10155 can include the 6recesses 10166, in which rollers (or ball bearings) 10177 are located,as seen in FIG. 51 .

It is noted that while the rollers 10177 and the associated recesses10166 are presented such that the rollers are proud of the outercircumference by about 50% of the diameter of the rollers, in analternate embodiment, the recesses and the rollers are sized anddimensioned such that only about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35 or 40 percentor more of the roller diameter extends proud of the outer circumference.In an alternate embodiment, the opposite is the case: a majority of theroller diameter extends proud of the outer periphery, and thus theaforementioned percentages can correspond to the amounts of the diameterthat is below the outer periphery. (All of the above is with respect toa roller/ball bearing that is pressed against the bottom of therecess/against the component 10155.)

Depending on how much interference exists between the component 10155,the roller 10166/ball bearing 10166, and the inside of the housing, theamount of torque that is required to cause the component 10155 to rotatecan be varied.

In an alternate embodiment, the flexibility of the housing can be usedto control the amount of torque that is required to cause the component10155 to rotate. In this regard, and oil canning effect with respect tothe sidewalls can be relied upon to impart a resistance that can beovercome upon a sufficient amount of torque to have the componentrotate. In an exemplary embodiment, the rollers or ball bearings couldbe fixed relative to the component 10155. Indeed, in an exemplaryembodiment, simple protrusions of the like can be located about theouter periphery of the component 10155. The ideas that as theprotrusions interfere with the sidewalls of the housing, the protrusionscause the housing to flex outward, and thus provide resistance againstthe rotation but permit the rotation.

An exemplary embodiment includes increasing the amount of magnetmaterial by doming the upper surface of the magnet (e.g., the centralportion, the entire magnet apparatus, etc.). In an exemplary embodiment,the doming can be such that it matches the curvature of the outersurface of the implant in that region. This is seen in FIG. 52 , whichdepicts a magnet apparatus 6861 that includes a central portion 6861 aand flanking portions 6861 b and 6861 c. in this exemplary embodiment,the overall polarity of the magnet apparatus 6861 is aligned along axis1234 as seen. That said, in an exemplary embodiment, a non-angled polaraxis can be utilized (aligned with the longitudinal axis 2112 ordiametrically aligned). In this exemplary embodiment, all three of themagnet apparatus are magnetic and they are magnetized in the samedirection. In this is that at least some exemplary embodiments, themagnet apparatus 6861 can be a monolithic structure. Conversely, in anexemplary embodiment, one or more of the flanking portions need not be amagnetic component/a permanent magnet and/or the central portion 6861 amay not be a permanent magnet. Any one or more these components can be anonmagnetic material such as that disclosed above.

FIG. 53 depicts a cross-sectional view of the magnet apparatus 6861,depicting how the upper surface is curved, corresponding to the domedsurface of FIG. 52 . In an exemplary embodiment, the dome surface isrotationally symmetric about axis 2112, while in other embodiments, thedome is not rotationally symmetric about axis 2112 or. In an exemplaryembodiment, when viewed from above, the overall magnet apparatus iscircular. Moreover, the dome can be a surface that has a constant radiusof curvature and/or has a varying radius of curvature from one side tothe other. In an exemplary embodiment, the dome surface is elliptical(e.g., half of an ellipse) while in other embodiments the dome surfaceis circular (can be, for example, a tenth or a 20^(th) or a 30^(th) or a50^(th), etc., of a circle. Any arrangement that can enable theteachings detailed herein can be utilized at least some exemplaryembodiments. FIG. 54 depicts an alternate exemplary embodiment of amagnet apparatus 6862 that has a domed top surface that has a lowerradius of curvature than that of the embodiment of FIG. 53 . FIG. 55depicts an exemplary embodiment of a magnet apparatus 6863 where boththe top and bottom are domed.

In an exemplary embodiment, the external component retention force canbe increased by at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 40 or50% or any value or range of values therebetween in 0.1% increments,relative to that which would be the case with a flat surface, all otherthings being equal. In an exemplary embodiment, there can be thus anincreased retention force which can mean that the external coil is lesslikely to fall off during daily activities. In an exemplary embodiment,the dome can have a maximum height above an extrapolated flat surface(if the magnet apparatus was disk shaped) of 0.1, 0.15, 0.2, 0.25, 0.3,0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95,1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 mm or any value orrange of values therebetween in 0.01 mm increments. In an exemplaryembodiment, the aforementioned values are the maximum height of the domerelative to a flat/disk shaped magnet, and/or the radius of curvature ofthe dome (at least in some locations), etc. An exemplary embodiment hasa radius of curvature at at least one location of 1, 1.5, 2, 2.5, 3,3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75,80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200,225, 250, 275, 300, 325, 350, 375, 400, 450 or 500 mm or more or anyvalue or range of values therebetween in 0.1 mm increments.

In view of the above, it can be seen that embodiments include animplantable medical device, comprising a magnet apparatus, which can bea monolithic body or made up of a plurality of components, and a bodyencompassing the magnet, wherein the magnet apparatus has a circularcross-section on a plane normal to a longitudinal axis of the magnetapparatus with a dome shape on top. In an exemplary embodiment, the domeis a 0.1 to 1.0 mm dome, 0.2 to 0.7 mm dome, a 0.3 to 0.6 mm dome, etc.

In an exemplary embodiment, the implantable medical device describedabove and/or below has a dome located only on one side of the magnetapparatus, while in other embodiments, the dome is located on both sidesof the magnet apparatus (and the domes need not be identical—the domescan have different configurations.

In an exemplary embodiment, there is an implantable medical device asdescribed above and/or below, wherein the dome is located only on bothsides of the magnet apparatus and the magnet apparatus is notsymmetrical about a plane that bisects the circular portion in half thatdoes not extend through the dome.

In an exemplary embodiment, as compared to a disk, where the tops andbottoms are flat and parallel to each other, the magnet apparatus 6861is such that the amount of magnetic material is greater than at least 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,40, 41, 42, 43, 44, 45, 46, 47, 48, 40 or 50% or more or any value orrange of values therebetween in 0.1% increments, relative to that whichwould be the case with a flat surface, all other things being equal. Thedome/portions above the flat section would be located if the magnetapparatus was a disk, can constitute at least 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 40 or 50% or more or any value or range of valuestherebetween in 0.1% increments of the amount of the magnetic materialof the magnet apparatus.

Some additional features of devices and systems and methods that preventthe magnet group from rotating in some embodiments, and enhance rotationin other embodiments, will be described in greater detail below. Firsthowever, some exemplary methods will now be described.

Accordingly, now with reference to FIG. 15 , which presents an exemplaryflowchart for an exemplary algorithm for an exemplary method, method1500, there is an exemplary method in an exemplary embodiment, there isan exemplary method that includes method action 1510 which includesobtaining access to a recipient of a medical device including a magnetgroup implanted in the recipient. Method 1500 also includes methodaction 1520, which includes exposing the recipient and the magnet groupto an MRI field of at least 1 T without removing the magnet group andwithout the magnet rotating. Any disclosure herein of exposure of theimplantable component to an MRI magnetic field or otherwise to amagnetic field corresponds to a disclosure of an exemplary embodimentwhere that magnetic field is applied in a direction that imparts maximumtorque onto the magnet/magnet apparatus/magnet group, etc. Accordingly,the aforementioned MRI field of at least 1 T can, in some embodiments,but not in others, the exposing the direction that imparts the maximumtorque onto the implanted magnet. Further, any disclosure herein ofexposure of the implantable component to an MRI magnetic field orotherwise to a magnetic field corresponds to a disclosure of anexemplary embodiment where that magnetic field is applied in a directionthat is parallel to and aligned with the longitudinal axis of theimplant (e.g., with respect to the cochlear implant 300 above, parallelto the line from the point where the array 118 enters the body 199 tothe center point of the screw 222 in the view of FIG. 6U) and alsocorresponds to an alternate disclosure of an exemplary embodiment wherethe magnetic field is applied in a direction that is perpendicular tothe longitudinal axis of the implant. In an exemplary embodiment, any ofthese aforementioned magnetic fields can be applied in a direction thatis parallel to the tangent surface of the skin immediately above theimplant and/or perpendicular to the tangent surface of the skinimmediately above the implant. In an exemplary embodiment, any of theseaforementioned magnetic fields can be applied in a direction that is 0,5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90,95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160,165, 170, 175 or 180 degrees or any value or range of valuestherebetween in 1° increments about the longitudinal axis as measuredfrom a location that is perpendicular to the bottom surface of theimplant (either direction) and/or angled relative to the longitudinalaxis (as measure from the longitudinal axis), and/or about an axis thatis normal to the longitudinal axis that is also normal to the bottomsurface of the implant.

Still with respect to FIG. 15 , in an exemplary embodiment, methodaction 1520 can include exposing the recipient and the magnet group toan MRI field of at least 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7,7.5 or 8 T or any value or range of values therebetween in 0.1 Tincrements without removing the magnet group and without the magnetrotating. In an alternate embodiment of this exemplary embodiment, themagnet group rotates but only a limited amount, such as any of theamounts detailed above. In an exemplary embodiment, the aforementionedmagnetic fields are applied in any one or more of the aforementionedregimes, including, for example, some regimes that results in maximumtorque being applied to the magnet apparatus.

Corollary with the teachings detailed above, it is noted that in someembodiments, any rotation can include rotation of the overall housing inwhich the magnet group is located/magnet apparatus is located, if suchis applicable. Again, in some embodiments, it is possible that thehousing rotates with the magnets upon the application of a sufficienttorque onto the magnets, and that rotation can be in a one-to-onerelationship.

FIG. 16 presents another exemplary flowchart for an exemplary algorithmfor an exemplary method, method 1600, where there is an exemplary methodaction 1610 which includes obtaining access to a recipient of a medicaldevice including a magnet group implanted in the recipient. Method 1500also includes method action 1620, which includes exposing the recipientand the magnet group to an MRI field of at least 1 T without removingthe magnet group and with the magnet rotating.

The aforementioned values of 1 T can be replaced with any of the valuesdetailed herein in alternative embodiments. Thus, as with the embodimentof FIG. 15 , in an exemplary embodiment,

Still with respect to FIG. 16 , in an exemplary embodiment, methodaction 1620 can include exposing the recipient and the magnet group toan MRI field of at least 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7,7.5 or 8 T or any value or range of values therebetween in 0.1 Tincrements without removing the magnet group and with the magnetrotating.

In an exemplary embodiment of some of the methods, prevention ofrotation of the magnet group/magnet apparatus that occurs results in themagnet having an orientation that is maintained for at least 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 26, 27, 28, 29 or 30, or 35 or 40 or 45 or 50 or 55 or 60 yearsor more or any value or range of values therebetween in one dayincrements. This can be the case irrespective of whether or not themagnet rotates upon the exposure to the magnetic field. In theembodiment where the magnet rotates, that can be the first time that themagnet group was rotated since implantation (if there was rotationduring implantation). That said, in some embodiments, the magnet groupwill never rotate the life of the implant a long as the implant isimplanted into the recipient, irrespective of the magnetic field appliedthereto (or at least one or more of the magnetic fields detailedherein).

Orientation of the magnet group can be determined by taking apredetermined arbitrary point on the magnet group (e.g., one or both ofthe locations on the circumference where the first magnet portion endsand the second portion begins) and/or can be determined based on themagnetic field (which can be determined using a device that can measurea magnetic field and/or determine a direction of the magnetic field—lowtech could be to put a compass at a fixed location from the magnet andsee how the compass changed). The field might not shift at all (otherthan the normal flexure) or may shift no more than 1, 2, 3, 4, 5, 6, 7,8, 9, or 10 degrees or any value or range of values therebetween in 0.1°increments.

FIG. 17 presents an exemplary algorithm for an exemplary method, method1700, according to an exemplary embodiment. Method 1700 includes methodaction 1710, which includes subjecting a magnet implanted in animplanted medical device implanted in a head of a recipient to amagnetic field. Note that the magnet can be the monolithic magnet groupor can be one of the three magnets—this could entail subjecting allthree of the magnets to the magnetic field, and thus method action 1710is met—method action 1710 can be executed by only subjecting one magnetto the field as well. Method 1700 also includes method action 1720,which includes rotating the magnet of the implanted medical device as aresult of exposure to the magnetic field. In this exemplary embodiment,the implanted medical device resists rotation of the magnet, but themagnetic field overcomes the resistance. In an exemplary embodiment, thebushing arrangement in a variation of FIG. 6T2 is utilized, where thebushing is interference fitted into the hole through the magnet groupand also interference fitted around the cylindrical housing wall thatextends from the bottom to the top of the housing so that there is ahigh friction force between the various components. Indeed, in anexemplary embodiment, a torque of more than 100 inch-pounds is requiredto be applied to the magnet group to turn the magnet group. In analternate exemplary embodiment, the implanted medical device does notresist rotation of the magnet. Indeed, in an exemplary embodiment, theimplanted medical device has a housing and magnet group apparatus thatis lubricated and utilizes the bearings apparatus of FIG. 6T3. In anexemplary embodiment, a torque of 0.1 inch-pounds is sufficient to turnthe magnet group. In an exemplary embodiment where the magnet rotates byovercoming resistance to rotation, this is the first time that themagnet rotates since implantation and/or since the last time that therecipient was exposed to an MRI field. In an exemplary embodiment, themagnetic field of at least 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6,6.5, 7, 7.5, 8, 8.5, 9 T or any value or range of values therebetween in0.1 T increments that is required to be applied in the method to achievethe rotation of the magnet in method action 1720, which rotation can beany of the rotations detailed herein. This magnetic field can be appliedat any of the directions detailed herein and/or variations thereof.

FIG. 18 presents an exemplary algorithm for an exemplary method, method1800, according to an exemplary embodiment. Method 1800 includes methodaction 1810, which includes subjecting a magnet implanted in animplanted medical device implanted in a head of a recipient to amagnetic field. Note that the magnet can be the monolithic magnet groupor can be one of the three magnets—this could entail subjecting allthree of the magnets to the magnetic field, and thus method action 1810is met—method action 1810 can be executed by only subjecting one magnetto the field as well. Method 1800 also includes method action 1820,which includes rotating the magnet of the implanted medical device as aresult of exposure to the magnetic field. In this exemplary embodiment,the implanted medical device resists rotation of the magnet, but themagnetic field overcomes the resistance. In other embodiments, there isno resistance. Still further, in other embodiments, there is residence,and such is substantial. Method 1800 also includes method action 1830,which includes removing the recipient from the magnetic field, whereinafter removing the recipient from the magnetic field, an orientation ofa magnetic field of the magnet has changed to a second orientationrelative to that which was the case when the external medical device waslas held against the recipient prior to exposure to the magnetic fieldand/or the orientation right before application of the magnetic field.In an exemplary embodiment, change in the orientation is rotation aboutthe longitudinal axis of the magnet group of more than or less than orequal to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220,230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, or 350degrees, or any value or range of values therebetween in 1° increments.In an exemplary embodiment, the implanted medical device maintains thatsecond orientation after removal from the magnetic field due to theresistance to the rotation. In an exemplary embodiment, the orientationis maintained within at least 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6,7, 8, 9, or 10 degrees or any value or range of values therebetween in0.1° increments due to the resistance to the rotation. Theaforementioned maintenance of the orientation occurs even after a methodaction that includes replacing the external component onto the recipientsuch that the implanted magnet group retains the external componentagainst the skin of the recipient as a result of magnetic attractionbetween the implanted magnet group and a ferromagnetic material theexternal component.

In an exemplary embodiment, the magnetic field of the methods above arean MRI magnetic field. The MRI field can have any of the strengthsherein. In an exemplary embodiment, the magnetic field is the magneticfield of another magnet, such as the external device. The magnet of theexternal device can be any of the strengths detailed herein.

FIG. 19 presents an exemplary algorithm for an exemplary method, method1900, according to an exemplary embodiment. Method 1900 includes methodaction 1910, which includes subjecting a magnet implanted in animplanted medical device implanted in a head of a recipient to amagnetic field. Note that the magnet can be the monolithic magnet groupor can be one of the three magnets—this could entail subjecting allthree of the magnets to the magnetic field, and thus method action 1910is met—method action 1910 can be executed by only subjecting one magnetto the field as well. Method 1900 also includes method action 1920,which includes rotating the magnet of the implanted medical device as aresult of exposure to the magnetic field. In this exemplary embodiment,the implanted medical device resists rotation of the magnet, but themagnetic field overcomes the resistance. Method 1900 also includesmethod action 1930, which includes removing the recipient from themagnetic field, wherein after removing the recipient from the magneticfield, an orientation of a magnetic field of the magnet has changed to asecond orientation relative to that which was the case when the externalmedical device was held against the recipient prior to exposure to themagnetic field. In an exemplary embodiment, change in the orientation isrotation about the longitudinal axis of the magnet group of more than orequal to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220,230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, or 350degrees or any value or range of values therebetween in 1° increments.In an exemplary embodiment, the implanted medical device does notmaintain the second orientation after removal from the magnetic field.In an exemplary embodiment, there is no resistance to the rotation (thebearing apparatus of FIG. 6T3 can be used in some embodiments). In anexemplary embodiment, within a day or two or three or four or five orthe next time that the recipient attaches the external medical device,the orientation changes by at least 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55,or 60 degrees or more, or any value or range of values therebetween in0.1° increments due to the lack of resistance to rotation. The changecan be a result of a method action that includes replacing the externalcomponent onto the recipient such that the implanted magnet groupretains the external component against the skin of the recipient as aresult of magnetic attraction between the implanted magnet group and aferromagnetic material the external component.

In this regard, in an exemplary embodiment, the magnet of the implantedmedical device becomes automatically reoriented to be aligned with themagnet of the external device upon reattachment of the external medicaldevice to the recipient. That said, in an alternate embodiment, thisdoes not happen.

Consistent with the teachings above, in an exemplary embodiment, thereis a method according to any of the teachings herein that furtherincludes the action of reattaching the external medical device to therecipient by reestablishing a magnetic connection between the externalmedical device and the magnet of the implanted medical device. In someembodiments as noted above, the second orientation is maintained whilethe external medical device is attached to the recipient and afterwards,while in other embodiments, the second orientation changes to anotherorientation, such as that prior to the second orientation, or anotherorientation, while the external medical device is attached to therecipient.

It is also noted that, in some embodiments, such as where there is amodicum of flexure associated with the components in, the device limitsany change from the new orientation to no more than 1, 2, 3, 4, 5, 6, 7,8, 9, or 10 degrees.

In some embodiments, the orientation of the external medical device whenreattached and subsequently attached is the same as that which was thecase when the external medical device was attached to the recipientprior to the action of removing the external medical device from therecipient. In some embodiments, the orientation of the external medicaldevice when reattached and subsequently attached is within 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 degrees, orany value or range of values therebetween in 0.1 degree increments ofthat which was the case when the external medical device was attached tothe recipient prior to the action of removing the external medicaldevice from the recipient. In an exemplary embodiment, the orientationsof the external device are controlled by the orientation of themagnet/magnet group of the implanted device having the new orientation.In an exemplary embodiment, the orientations the external device areindependent of the orientation of the implanted magnet. The implantedmagnet orientation does not affect the orientation of the externalcomponent. In an exemplary embodiment, the orientation of the externalcomponent is controlled by or otherwise more influenced at least by awire that extends from the antenna component of the external componentto a behind the ear device, which wire, while flexible, imparts a forcehowever minimal onto the coil component of the external component. Inthis regard, in an exemplary embodiment, when the external component isreattached, the orientation of the external device is the same as it wasprior to the orientation of the implanted magnet changing.

In an exemplary embodiment of the methods detailed above, such as wherethe orientation of the magnetic field has shifted at least 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 degrees ormore about the longitudinal axis of the magnet group (direction normalto the skin)/the longitudinal axis between the magnet group that isimplanted in the recipient and a magnet group of the external medicaldevice with respect to the second orientation relative to theorientation prior to exposure to the magnetic field and/or that which isthe case prior to removing the external component prior to exposure tothe magnetic field, the aforementioned orientations of the externalcomponent are achieved.

In at least some exemplary embodiments, the magnetic field of themethods above can be a magnetic field that is less than, greater thanand/or equal to 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5,1.75, 2, 2.25, 2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 9, 10,11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100,125, 150, 175, 200, 225, 250, 275, 300, 350, 400, 450, 500, 550, 600,700, 800, 900, or 1000 times or more (or any value or range of valuestherebetween in 0.1 increments) stronger than the magnetic fieldgenerated by the magnet(s) of the external medical device that is heldagainst the skin by the implantable magnets when that device was heldagainst the person via the magnetic connection between the two.

In an exemplary embodiment, the magnet of the implanted medical devicebecomes automatically reoriented to be aligned with the orientation ofthe external magnet upon reattachment of the external medical device tothe recipient. Alternatively, in an exemplary embodiment, the magnet ofthe external medical device becomes automatically reoriented to bealigned with the second orientation upon reattachment of the externalmedical device to the recipient. That is, the external magnet can rotatein some embodiments. In an exemplary embodiment, one or more of theconfigurations or features detailed herein associated with the implantedmagnet group and/or implanted magnet can be present in the externalcomponent as well. Indeed, in an exemplary embodiment, the magnetapparatus of the external component is effectively a duplicate of themagnet apparatus in the implant, while in other embodiments, the tubecan have differences. In an exemplary embodiment, the magnet apparatusof the external component can have any one or more or all of thefunctionalities of the magnet group/magnet of the implanted component.(Also, any method action detailed herein associated with the implantedmagnet components can be executed or otherwise associated with theexternal magnet components providing that the art enables such unlessotherwise noted.) In this regard, in an exemplary embodiment, there is amethod action that includes replacing the external component against theskin of the recipient such that the external component is magneticallyheld to the skin by a magnetic attraction between the implant and theexternal component, wherein the magnet/magnet group of the externalcomponent rotates at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55,60, 65, 70, 75, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180,190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320,330, 340, or 350 degrees or any value or range of values therebetween in1° increments. In an exemplary embodiment, the rotation is equal to orat least about equal to the amount of change to the orientation of themagnetic field/implanted magnet that results from exposure to themagnetic field in the methods detailed herein. In an exemplaryembodiment, the rotation is an amount that is less than, equal to orgreater than 70, 75, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92,93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108,109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 125, or 130%the amount of change in orientation that resulted in the secondorientation or any value or range of values therebetween in 1%increments.

An exemplary embodiment includes an exemplary method, comprising theaction of subjecting a magnet located in a housing implanted in animplanted medical device implanted in a head of a recipient to amagnetic field of an MRI machine of at least 1.5 T, or any of the valuesdetailed herein. In this method, there is further the action ofmaintaining an orientation of the magnet (apparatus or magnet group,etc.) relative to the housing while the magnet is exposed to themagnetic field, wherein the magnetic field imparts a torque onto themagnet, and wherein the magnet is diametrically magnetized. In thisembodiment, it is possible for the housing and the magnet to rotate. Inan alternate embodiment, neither the magnet nor the housing rotates, orat least the rotation is limited in accordance with the teachingsherein.

In an exemplary embodiment, the magnet is part of a magnet group thatincludes two flanking magnets that are axially magnetized. In anexemplary embodiment, the the magnet is part of a magnet apparats thatincludes two flanking components that are non-magnetic components andare also located in the housing. In an alternate embodiment, the twoflanking components are located outside the housing.

In an exemplary embodiment of this method, there is the action ofremoving the recipient from the magnetic field, wherein after removingthe recipient from the magnetic field, an orientation of a magneticfield of the magnet has not changed. An exemplary embodiment of thismethod includes the action of reattaching an external medical device tothe recipient by reestablishing a magnetic connection between theexternal medical device and the magnet of the implanted medical device,wherein the attachment force between the external medical device and theimplant is the same as that which was the case prior to the exposure tothe 1.5 T magnetic field or whatever field that is the subject of thismethod.

An exemplary embodiment of this method also is such that as a result ofthe method, the orientation of the external medical device whenreattached and subsequently attached is effectively the same as thatwhich was the case when the external medical device was attached to therecipient prior to the action of removing the external medical devicefrom the recipient. Also, in an exemplary embodiment, as a result of themethod, the exposure to the magnetic field takes place at least 6 monthsafter implantation of the magnet and the magnet has effectively neverrotated relative to the implanted medical device prior the exposure tothe magnetic field.

Embodiments include an assembly, comprising a housing, such as any ofthe housings detailed herein, and a magnet apparatus (e.g., any of themagnet groups disclosed herein, or a single magnet/magnet that is asingle portion) in the housing. In an exemplary embodiment, the magnetapparatus is configured to provide an axial magnetic flux outside thehousing as the strongest magnetic force relative to a diametrical fluxand/or a non-axial magnetic flux, if present, existing outside thehousing. In an exemplary embodiment, the magnet apparatus has asubstantial portion thereof that generates a diametrical flux. In thisregard, FIG. 6X depicts a magnet group 679Imp and a magnet group 697Ext,the groups of the respective implanted and external components. Bothgroups are housed in housings 688Imp and 688Ext, respectively. As can beseen, the magnet groups generate a magnetic flux that has an axialportion (the vertical portion—it is axial because it is parallel withthe axial direction of the magnet group/the longitudinal direction) thatis located outside the housing and a diametrical portion (the horizontalportion—it is diametrical because it is in the direction of the diameterof the magnet group). The axial flux is at least 1.05, 1.1, 1.15, 1.2,1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3,2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7,3.8, 3.9, or 4 times or more, or any value or range of valuestherebetween in 0.05 increments stronger than the other flux and/ordiametrical flux. It is noted that in some alternate embodiments, asdetailed above, the flanking magnets and/or the central magnet may notbe present, and otherwise may be a nonmagnetic component, in which casethe magnetic fields will be difference as would be understood than thatdepicted in FIG. 6X. Still further, it is noted that in some alternateembodiments, as detailed above, the flanking magnets will have sidesthat are aligned with the central magnet, and in other alternateembodiments, the magnets can all have polar alignments that are arrayedin the vertical direction. In an exemplary embodiment, the resultingfluxes can still be any of the values detailed herein and/or variationsthereof, if such is applicable.

Embodiments include an assembly, comprising a housing, such as any ofthe housings detailed herein, and a magnet apparatus (e.g., any of themagnet groups disclosed herein, or a single magnet/magnet that is asingle portion) in the housing. In an exemplary embodiment, the magnetapparatus is configured to provide an axial magnetic flux outside thehousing as the strongest magnetic force relative to a diametrical fluxand/or a non-axial magnetic flux, if present, existing outside thehousing. In an exemplary embodiment, the magnet apparatus has asubstantial portion thereof that generates a diametrical flux. In anexemplary embodiment, the magnet apparatus generates a magnetic field asmeasured at 2, 3, 4, 5, 6, 7, and/or 8 mm away from the apparatus thatis at least 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.6,1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1,3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, or 4 times or more, or any valueor range of values therebetween in 0.05 increments stronger than theflux that would result if the magnet apparatus had all portionsgenerating only respective fluxes that are more aligned with the axialdirection (e.g., a single monolithic magnet, such as a disc-shapedmagnet, with the N-S axis aligned vertically, or a magnet group having aplurality of portions, all of which have the north south and/or southnorth axis aligned vertically) or if the apparatus had all portionsgenerating only respective fluxes that are more aligned with the radialdirection (e.g., a single monolithic magnet, such as a disk-shapedmagnet, within a N-S axis aligned horizontally, or a magnet group havinga plurality of portions, all of which have the north south and/or southnorth axis aligned horizontally), as measured at the same relativelocation, all other things being equal. In an exemplary embodiment, thelocation of measurement is at a location that is normal to a face of themagnet apparatus at one of the aforementioned distances as measuredabove a location that is 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55,60, 65, 70, 75, 80, 85, 90, 95, or 100% of the way across the face ofthe magnet apparatus as measured at one of its longest or shortestdimension on the skin facing face thereof.

Further, in an exemplary embodiment, there is a medical device,comprising an implantable component including a first magnet apparatus(e.g., magnet apparatus 697Imp), and an external component including asecond magnet apparatus (e.g., magnet apparatus 967Ext). The firstmagnet apparatus includes a first portion that generates a first fluxthat is more aligned with an axial direction of the device (e.g., one ofthe portions that have the N-S axis aligned in the vertical) and asecond portion that generates a second flux that is more aligned with adirection normal to the axial direction (e.g., the portion in thecenter, having the S-N axis aligned horizontally). In this embodiment,the magnetic force between the implantable component and an externalcomponent is stronger than that which would be the case if the firstmagnet apparatus had all portions generating only respective fluxes thatare more aligned with the axial direction (e.g., a single monolithicmagnet, such as a disc-shaped magnet, with the N-S axis alignedvertically, or a magnet group having a plurality of portions, all ofwhich have the north south and/or south north axis aligned vertically)or if the first magnet apparatus had all portions generating onlyrespective fluxes that are more aligned with the radial direction (e.g.,a single monolithic magnet, such as a disk-shaped magnet, within an N-Saxis aligned horizontally, or a magnet group having a plurality ofportions, all of which have the north-south and/or south-north axisaligned horizontally). All of this is based on the qualifier that allother things are equal. That is, for example, the material that makes upthe magnet apparatuses are the same, the volumes and densities andshapes are all the same, any spacing associated with the components ofthe same, the housing in which the magnets might be located are thesame, etc. This as opposed to, for example, a magnet that has a largeror smaller diameter or larger or smaller thickness or is made up of adifferent type of magnetic material or is not as “aggressively”magnetized as the comparison or is more “aggressively” magnetized, etc.FIG. 6Y presents an exemplary chart presenting exemplary data for forceversus magnet distances for magnet apparatuses that are aligned with oneanother in a manner akin to that of FIG. 6X but spaced away from oneanother (the distance is being from the closest surfaces and/or from thecenters of gravity and/or the geometric centers of the magnetapparatuses), where 681 is for an axial aligned arrangement (bothexternal and internal magnet apparatuses), 682 is for a diametricallyaligned arrangement (both external and internal magnet apparatuses) and683 is for the arrangement seen in FIG. 6X. It is noted that in theabove-described embodiment, only qualifiers have been applied to themagnet apparatus of the implant (other than the all things being equalqualifier which applies to everything), and thus the magnet apparatus ofthe external component can be a same type or a different type of magnetthan that detailed. In this regard, the magnet apparatus of the externalcomponent can be a magnet apparatus that has all portions thereof (itcan be a monolithic component or separate components—it can also haveonly one portion) having magnetization in the same direction (axial,diametric, etc.). In an exemplary embodiment, the external component canhave a magnet apparatus that is a monolithic disc magnet (working themagnet group) or a cylindrical magnet that has the north-south axis (orthe group of axes) aligned in the axial direction. In an exemplaryembodiment, the external component can have a magnet apparatus that is amonolithic disc magnet or a cylindrical magnet that has a north-southaxis (or group of axes) aligned in the diametric direction. In anexemplary embodiment, for one or both of these alternate arrangements,the force curves for a given distance can be greater than, less than orequal to 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, or 1.5times or more, or any value or range of values therebetween in 0.01increments of that shown in FIG. 6Y (e.g., the force can be increased by1.06 times or decreased by 1.06 times at the 5 mm separation, and beincreased or decreased 1.08 times at the 5.25 separation, etc.). Notealso that the axes can be offset from perfectly axial and perfectlydiametrical. In an exemplary embodiment, the flux for an externalaxially aligned magnet can have the flux that flows through a center ofthe magnet (where there is a north-south alignment with the north polefacing the implant) to the south pole of the axially aligned implantedmagnet and in the flux flows through the diametrically aligned magnet tothe magnet on the end with the north pole facing the external magnet,and then the flux flows from the north pole of that magnet around theexternal magnet to the south pole which faces away from the implantedmagnet, and so on.

In an exemplary embodiment, the magnet apparatus is disk shaped, whilein other embodiments, the magnet apparatus is rectangular shaped, and inother embodiments, it is cylindrical shaped (anything where the diameteris less than half the height shall be considered cylindrical as that isused herein). In an exemplary embodiment, as seen in FIG. 6X, the magnetapparatus has a component thereof that generates a diametrically alignedmagnetic flux at a geometric center of the magnet apparatus. This asopposed to the embodiments where there is a hole at the center, and thusdo not generate such a flux at the geometric center.

In an exemplary embodiment, consistent with the teachings above, thehousing and magnet apparatus are parts of an implantable component ofthe medical prosthesis, the medical prosthesis includes an externalcomponent that includes a respective magnet apparatus, and the medicalprosthesis is configured to hold the external component against skin ofthe recipient via the axial magnetic flux.

In an exemplary embodiment, there is a medical prosthesis, comprising ahousing and a magnet apparatus in the housing, wherein the magnetapparatus is configured to provide an axial magnetic flux outside thehousing as the strongest magnetic force relative to a diametrical flux,if present, outside the housing and the magnet apparatus is configuredto rotate about the axial direction, wherein the axial direction is atleast generally normal to skin of a recipient when the medicalprosthesis is used with a recipient.

In an exemplary embodiment, the magnetic force between the magnetapparatus of the implantable component and the magnet apparatus of theexternal component, when positioned as would be positioned when used ona recipient at a distance of ABC mm away from each other, is at leastand/or equal to and/or no greater than XYZ times that which would be thecase with respect to purely axial polarity magnets of the same size andsame mass and same material magnetized at a maximum magnetism whilestill being usable as a medical prosthesis. ABC can be any value orrange of values shown on the chart on FIG. 6Y, in 0.1 mm increments, andcan be smaller or larger (e.g., 0 mm to 20 mm, all in 0.1 mm increments.YZX can be 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.6,1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7,2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.25,4.5, 4.75, 5, 5.5, 6, 6.5, 7, 7.5, 8 or any value or range of valuestherebetween in 0.01 increments. XYZ can also be converted to apercentage (e.g., 1.05 times would be 5% greater, etc.). These valuescan be for the arrangement of FIG. 6X, or for the variation thereofwhere the external magnet apparatus has the different configurationsdetailed above.

In an exemplary embodiment, there is an apparatus as detailed hereinwherein the magnetic force between the magnet apparatus of theimplantable component and the magnet apparatus of the externalcomponent, when positioned as would be positioned when used on arecipient at a distance of three mm away from each other, is at least100% greater than that which would be the case with respect to purelydiametrical polarity magnets of the same size and same mass and samematerial magnetized at a maximum magnetism while still being usable as amedical prosthesis. In this regard, it is noted that at least someembodiments herein associated with comparisons to other designs are atcomparisons where the magnets are magnetized to their maximummagnetization capacity.

In some embodiments, the implanted and/or the external magnet apparatusis configured to rotate relative to the remainder of the respectiveinternal and/or external component (which includes the embodiments wherea minimum torque is needed to start the rotation (initially resists, andthen rotates). In some embodiments, the implanted and/or the externalmagnet apparatus is configured to not rotate relative to the remainderof the respective internal and/or external component (different from theembodiments where a minimum torque is needed to start the rotation(initially resists, and then rotates). In some embodiments, one rotatesand the other does not. In some embodiments, both rotate. In someembodiments, no magnet apparatus rotates. Thus, in some embodiments, themagnet apparatus of the external component is configured to rotaterelative to the remainder of the external component, and the magnetapparatus of the implantable component drives the orientation of themagnet apparatus of the external component (this can be a result of theimplantable component not rotating at all, and also a result of theimplantable component having rotated but then being fixed because atorque is not applied that is strong enough to have the magnet rotatemore). Thus also, in some embodiments, the magnet apparatus of theimplanted component is configured to rotate relative to the remainder ofthe implanted component, and the magnet apparatus of the externalcomponent drives the orientation of the magnet apparatus of theimplantable component (this can be a result of the external componentnot rotating at all, and also a result of the external component havingrotated but then being fixed because a torque is not applied that isstrong enough to have the magnet rotate more). In an exemplaryembodiment, the housing and the magnet apparatus establish ahousing-magnet apparatus assembly (of the internal component or theexternal component, respectively—both can have such as well). The(respective) housing-magnet apparatus assembly is configured to resistrotation of the magnet apparatus within the housing for magnet fieldsbelow ZKW Tesla, where ZKW can be 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75,2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75, or 5 ormore, or any value or range of values therebetween in 0.05 increments,where these fields are aligned, in some embodiments, and not others, toimpart at least about maximum torque onto the magnet apparatus. The(respective) housing-magnet apparatus assembly is configured to enablerotation of the magnet apparatus within the housing for magnet fieldsonly larger than ZKW Tesla (so aligned as detailed above), in some otherembodiments.

In an exemplary embodiment, the implant is configured such that themagnet group or magnet apparatus or magnet resists rotation as a unitrelative to the housing (here, there is a housing containing the magnet)about an axial direction with respect to a first torque range appliedabout the axial direction to the magnet group/apparatus/magnet, whereinthe first range is a range that includes a torque that causes thehousing and the magnet group to rotate relative to a remainder of theapparatus. Here, the housing and the magnet are such that any rotationthat occurs will be one to one rotation, and will result in the torqueovercoming the friction between the silicone body and the housing, forexample. Also, in an exemplary embodiment, the implant is configuredsuch that the magnet group, etc., resists rotation as a unit relative tothe housing about an axial direction with respect to a first torquerange applied about the axial direction to the magnet group, wherein thefirst range is a range that includes a torque that causes the apparatusto fail due to the torque. For example, the housing will pop out of thesilicone body 170, the silicone body will rip apart, or otherwiseplastically deform, etc. In an exemplary embodiment, the first torquerange can be a range of torques according to any of the ranges herein,and can be a range that includes zero to 0.1, 0.15, 0.2, 0.25, 0.5,0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30,35, 40, 45 or 50 or 60 or 70 or 80 or 90 or 100 or more inch-pounds orany value or range of values therebetween in 0.05 inch-pound increments.

It is noted that any disclosure of a device and/or system hereincorresponds to a disclosure of a method of utilizing such device and/orsystem. It is further noted that any disclosure of a device and/orsystem herein corresponds to a disclosure of a method of manufacturingsuch device and/or system. It is further noted that any disclosure of amethod action detailed herein corresponds to a disclosure of a deviceand/or system for executing that method action/a device and/or systemhaving such functionality corresponding to the method action. It is alsonoted that any disclosure of a functionality of a device hereincorresponds to a method including a method action corresponding to suchfunctionality. Also, any disclosure of any manufacturing methodsdetailed herein corresponds to a disclosure of a device and/or systemresulting from such manufacturing methods and/or a disclosure of amethod of utilizing the resulting device and/or system.

Unless otherwise specified or otherwise not enabled by the art, any oneor more teachings detailed herein with respect to one embodiment can becombined with one or more teachings of any other teaching detailedherein with respect to other embodiments. Also, unless otherwisespecified or otherwise not enabled, any one or more teachings detailedherein can be excluded from combination with one or more otherteachings, in some embodiments.

Thus, any of the magnet portion arrangements disclosed herein can beused anywhere (internal and/or external) and any of the featuresdescribed with respect to the magnet arrangement of FIG. 6A for example,can be used with that of FIG. 7A, etc., and vice versa.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. It will be apparent to persons skilled in the relevant artthat various changes in form and detail can be made therein withoutdeparting from the spirit and scope of the invention. Thus, the breadthand scope of the present invention should not be limited by any of theabove-described exemplary embodiments but should be defined only inaccordance with the following claims and their equivalents.

FIG. 7A is a perspective view of a magnet group 700 in accordance withanother example of the technology. Many of the components are generallynumbered consistently with the components of FIG. 6A, but beginning with700, and not all elements thereof are necessarily described further.Magnet group 704 also includes a third magnet 704 e that includes twodiscrete magnets, disposed between magnets 704 a and 704 b. Similarly,magnet group 706 also includes a third magnet 706 f, disposed betweenmagnets 706 c and 706 d. Here, magnets 704 e and 706 f are substantiallywedge-shaped. FIG. 7B is a plot showing retention force versus magnetseparation for the magnet group 700 of FIG. 7A. FIG. 7C is a plotshowing battery force versus magnet separation for the magnet group 700of FIG. 7A. The forces plotted in both are based on a separationdistance of the external and implantable magnet groups 704, 706, and arecompared to plots depicted in FIGS. 8B and 8C below in an exemplaryembodiment, bushing 655 is interference fitted.

FIG. 8A is a perspective view of a magnet group 800 in accordance withanother example of the technology. This magnet group 800 is identical tothe magnet group 600 depicted FIG. 6A and thus not all elements thereofare necessarily described further. Here, magnets 804 e and 806 f aresubstantially trapezoidal. FIG. 8B is a plot showing retention forceversus magnet separation for the magnet group 800 of FIG. 8A. This plotpresents the same information as the plot of retention force versusmagnet separation for the magnet group 600, as depicted in FIG. 6A. Ascompared to the plots of FIGS. 7B and 7C, it can be concluded that theshapes of the diametrically magnetized third magnets (e.g., 704 e, 706 fin FIG. 7A; and 804 e, 806 f in FIG. 8A) are not critical. FIG. 8C is aplot showing battery force versus magnet separation for the magnet group800 of FIG. 8A. This plot presents the same information as the plot ofbattery force versus magnet separation for the magnet group 600, asdepicted in FIG. 6A. The reduced battery force depicted in FIG. 8Cindicates that the configuration of magnet group 800 might be slightlymore desirable than that of magnet group 700.

FIG. 9A is a perspective view of a magnet group 900 in accordance withanother example of the technology. External magnet group 904 includesaxially magnetized magnets 904 a, 904 b (in two parts), and 904 g.Additionally, diametrically magnetized magnets 904 e and 904 i (both intwo parts) are depicted. Implantable magnet group 906 includes axiallymagnetized magnets 906 c, 906 d (in two parts), and 906 h. Additionally,diametrically magnetized magnets 906 f and 906 j (both in two parts) aredepicted. Similarly referenced magnetization directions are alsoindicated. FIG. 9B is a plot showing retention force versus magnetseparation for the magnet group 900 of FIG. 9A. As compared to theretention force plots of FIGS. 7B and 8B, the increased number ofmagnets depicted in FIG. 9A results in only slight improvement toretention force at shorter separation distances. Retention force atgreater separation distances is worse. FIG. 9C is a plot showing batteryforce versus magnet separation for the magnet group 900 of FIG. 9A.Notably, battery force shows a significant overall decrease, as comparedto the battery forces depicted in FIGS. 7C and 8C of magnet group 900.This indicates that the use of more magnets leads to a marked decreasein battery force.

FIG. 10A is a perspective view of a magnet group 1000 in accordance withanother example of the technology. Many of the components are generallynumbered consistently with the components of FIG. 7A, but beginning with1000, and not all elements thereof are necessarily described further.Notably here, a deflector 1002 is disposed above magnets 1004 a and 1004b. FIG. 10B is a plot showing retention force versus magnet separationfor the magnet group 1000 of FIG. 10A. As compared to the retentionforce plots of FIGS. 7B and 8B, use of a deflector somewhat lowersretention force, mostly for a small separation distance. FIG. 10C is aplot showing battery force versus magnet separation for the magnet group1000 of FIG. 10A. As compared to the battery force plots of FIGS. 7C and8C, use of a deflector significantly lowers the battery force, to valueseven lower than the reference magnet group 400 incorporating adeflector. Thus, use of the deflector may be desirable for cases whereit is not possible to locate the battery at a favorable position as inFIG. 6B.

FIG. 11A is a perspective view of a magnet group 1100 in accordance withanother example of the technology. In this example, external magnetgroup 1104 is identical to the magnet group 1004 depicted FIG. 10A andthus not all elements thereof are necessarily described further.Implantable magnet group 1106 is identical to implantable magnet group406 depicted in FIG. 4 and thus not all elements thereof are necessarilydescribed further. FIG. 11B is a plot showing retention force versusmagnet separation for the magnet group 1100 of FIG. 11A. Here, retentionforce is lowered significantly, indicating that the benefits of magnetgroups having greater numbers of magnets can be lost unless such groupsare utilized in both the external and implantable magnet groups.Nevertheless, the magnet groups having a greater number of magnets arecompatible with currently existing implantable magnet groups having amagnet configuration as 1106 in FIG. 11A. FIG. 11C is a plot showingbattery force versus magnet separation for the magnet group 1100 of FIG.11A. This indicates that battery force is lower than that of theimplantable magnet group 400 of FIG. 4 .

In an exemplary embodiment, there is an implantable medical device,comprising: a magnet; and a body encompassing the magnet, wherein theimplantable medical device is configured to enable the magnet to rotate,with respect to exposure to a magnetic field, only under a magneticfield that is stronger than at least twice a magnetic field generated bythe magnet. In an exemplary embodiment, there is an implantable medicaldevice as described above and/or below, wherein the body is a case; andthe rotation is rotation relative to the case. In an exemplaryembodiment, there is an apparatus comprising the implantable medicaldevice as described above and/or below, an external component includinga second magnet, wherein the external component is held proximate theimplantable medical device via magnetic attraction between the magnetand the external magnet, and the implantable component is configuredsuch that the external component can be rotated 360 degrees relative tothe implantable medical device when the two components are within 10 mmof each other without the magnet rotating relative to the body and/orthe remainder of the implantable medical device, the rate of rotationbeing no more than 20 degrees per second. In an exemplary embodiment,there is an apparatus as described above and/or below, wherein theimplantable component is configured such that a magnet at least 10 timesthe strength of the magnet can be rotated 360 degrees relative to theimplantable medical device relative to a plane that is parallel to askin surface facing side of the implantable component when the twocomponents are within 5 mm of each other without the magnet rotatingrelative to the body and/or relative to the remainder of the implantablemedical device, the rate of rotation being no more than 20 degrees persecond.

In an exemplary embodiment, there is an implantable medical device asdescribed above and/or below, wherein: the implantable medical device isconfigured to enable the magnet to rotate only under very strongexternal magnetic fields. In an exemplary embodiment, there is animplantable medical device as described above and/or below, wherein: thebody is an enclosure that at least partially encloses the magnet; anddesigned friction between the body and/or a component within the bodyand the magnet prevents the magnet from rotating under a magnetic fieldthat is not as strong as the magnetic field that causes the magnet torotate. In an exemplary embodiment, there is an implantable medicaldevice as described above and/or below, wherein: the body is anenclosure that at least partially encloses the magnet; and pressureforce exerted by the body directly and/or indirectly onto the magnetprevents the magnet from rotating under a magnetic field that is not asstrong as the magnetic field that causes the magnet to rotate. In anexemplary embodiment, there is an implantable medical device asdescribed above and/or below, wherein: the body is an enclosure that atleast partially encloses the magnet; and high friction element(s)between and/or part of the body directly and/or indirectly in contactwith the magnet prevent(s) the magnet from rotating under a magneticfield that is not as strong as the magnetic field that causes the magnetto rotate.

In an exemplary embodiment, there is an apparatus comprising theimplantable medical device as described above and/or below, an externalcomponent including a second magnet, wherein the second magnet isrotatable within the external component. In an exemplary embodiment,there is an apparatus comprising an implantable medical device asdescribed above and/or below, and an external component including asecond magnet, wherein the second magnet is rotatable within theexternal component, and the external component is configured to enablethe second magnet to rotate under the magnetic field generated by themagnet when the external component is held proximate the implantablemedical device.

In an exemplary embodiment, there is a method, comprising: subjecting amagnet implanted in an implanted medical device implanted in a head of arecipient to a magnetic field; and rotating the magnet of the implantedmedical device as a result of exposure to the magnetic field, whereinthe implanted medical device resists rotation of the magnet, but themagnetic field overcomes the resistance. In an exemplary embodiment,there is a method as described above and/or below, further comprising:removing the recipient from the magnetic field, wherein after removingthe recipient from the magnetic field, an orientation of a magneticfield of the magnet has changed to a second orientation relative to thatwhich was the case when an external medical device was last held againstthe recipient prior to exposure to the magnetic field, the implantedmedical device maintaining that second orientation after removal fromthe magnetic field due to the resistance to the rotation. In anexemplary embodiment, there is a method as described above and/or below,further comprising: reattaching the external medical device to therecipient by reestablishing a magnetic connection between the externalmedical device and the magnet of the implanted medical device, whereinthe second orientation is maintained while the external medical deviceis attached to the recipient and afterwards. In an exemplary embodiment,there is a method as described above and/or below, wherein: theorientation of the external medical device when reattached andsubsequently attached is effectively the same as that which was the casewhen the external medical device was attached to the recipient prior tothe action of removing the external medical device from the recipient.

In an exemplary embodiment, there is a method as described above and/orbelow, wherein: the orientation of the magnetic field shifted at least30 degrees about a longitudinal axis between the magnet and a magnet ofthe external medical device with respect to the second orientationrelative to the orientation prior to exposure to the magnetic field. Inan exemplary embodiment, there is a method as described above and/orbelow, wherein: the orientation of the magnet has remained at leastsubstantially constant from the time of implantation of the implanteddevice to the time at least just before exposure to the magnetic field.In an exemplary embodiment, there is a method as described above and/orbelow, wherein: the action of subjecting the person to the magneticfield is such that the magnetic field is at least one of five (5) timesgreater than the magnet or at least greater than 0.5 T. In an exemplaryembodiment, there is a method as described above and/or below, wherein:the action of subjecting the person to the magnetic field is such thatthe magnetic field is at least one of five (5) times greater than thatcreated by the external medical device when the external medical devicewas held against the person via the magnetic connection or at leastgreater than 0.5 T. In an exemplary embodiment, there is a method asdescribed above and/or below, wherein: a magnet of the external medicaldevice becomes automatically reoriented to be aligned with the secondorientation upon reattachment of the external medical device to therecipient. In an exemplary embodiment, there is a method as describedabove and/or below, wherein: the exposure to the magnetic field takesplace at least 6 months after implantation of the magnet; and the magnethas effectively never rotated relative to the implanted medical deviceprior the exposure to the magnetic field.

In an exemplary embodiment, there is a medical prosthesis, comprising: ahousing; and a magnet apparatus in the housing, wherein the magnetapparatus is configured to provide an axial magnetic flux outside thehousing as the strongest magnetic force relative to a diametrical flux,if present, outside the housing; and the magnet apparatus is configuredto rotate about the axial direction, wherein the axial direction is atleast generally normal to skin of a recipient when the medicalprosthesis is used with a recipient. In an exemplary embodiment, thereis a medical prosthesis as described above and/or below, wherein: themagnet apparatus is disk shaped. In an exemplary embodiment, there is amedical prosthesis as described above and/or below, wherein: the magnetapparatus has a component thereof that generates a diametrically alignedmagnetic flux at a geometric center of the magnet apparatus. In anexemplary embodiment, there is a medical prosthesis as described aboveand/or below, wherein: the housing and magnet apparatus are parts of animplantable component of the medical prosthesis; the medical prosthesisincludes an external component that includes a respective magnetapparatus; and the medical prosthesis is configured to hold the externalcomponent against skin of the recipient via the axial magnetic flux. Inan exemplary embodiment, there is a medical prosthesis as describedabove and/or below, wherein: the magnetic force between the magnetapparatus of the implantable component and the magnet apparatus of theexternal component, when positioned as would be positioned when used ona recipient at a distance of three mm away from each other, is at least10% greater than that which would be the case with respect to purelyaxial polarity magnets of the same size and same mass and same materialmagnetized at a maximum magnetism while still being usable as a medicalprosthesis.

In an exemplary embodiment, there is a medical prosthesis as describedabove and/or below, wherein: the magnetic force between the magnetapparatus of the implantable component and the magnet apparatus of theexternal component, when positioned as would be positioned when used ona recipient at a distance of three mm away from each other, is at least25% greater than that which would be the case with respect to purelyaxial polarity magnets of the same size and same mass and same materialmagnetized at a maximum magnetism while still being usable as a medicalprosthesis. In an exemplary embodiment, there is a medical prosthesis asdescribed above and/or below, wherein: the magnetic force between themagnet apparatus of the implantable component and the magnet apparatusof the external component, when positioned as would be positioned whenused on a recipient at a distance of three mm away from each other, isat least 100% greater than that which would be the case with respect topurely diametrical polarity magnets of the same size and same mass andsame material magnetized at a maximum magnetism while still being usableas a medical prosthesis. In an exemplary embodiment, there is a medicalprosthesis as described above and/or below, wherein: the magnetapparatus of the external component is configured to rotate relative tothe remainder of the external component.

In an exemplary embodiment, there is a medical prosthesis as describedabove and/or below, wherein: the magnet apparatus of the externalcomponent is configured to rotate relative to the remainder of theexternal component; and the magnet apparatus of the implantablecomponent drives the orientation of the magnet apparatus of the externalcomponent. In an exemplary embodiment, there is a medical prosthesis asdescribed above and/or below, wherein: the housing and magnet apparatusestablish a housing-magnet apparatus assembly; and the housing-magnetapparatus assembly is configured to resist rotation of the magnetapparatus within the housing for magnet fields below 0.5 T.

In an exemplary embodiment, there is a medical prosthesis, comprising: ahousing; and a magnet apparatus in the housing, wherein the magnetapparatus is configured to provide an axial magnetic flux outside thehousing as the strongest magnetic force relative to a diametrical flux,if present, outside the housing; and the magnet apparatus is configuredto resist rotation about the axial direction, wherein the axialdirection is at least generally normal to skin of a recipient when themedical prosthesis is used with a recipient. In an exemplary embodiment,there is a medical prosthesis as detailed above and/or below, whereinthe magnet apparatus is disk shaped. In an exemplary embodiment, thereis a medical prosthesis as detailed above and/or below, wherein themagnet apparatus has a component thereof that generates a diametricallyaligned magnetic flux at a geometric center of the magnet apparatus. Inan exemplary embodiment, there is a medical prosthesis as detailed aboveand/or below, wherein: the housing and magnet apparatus are parts of animplantable component of the medical prosthesis; the medical prosthesisincludes an external component that includes a respective magnetapparatus; and the medical prosthesis is configured to hold the externalcomponent against skin of the recipient via the axial magnetic flux. Inan exemplary embodiment, there is a medical prosthesis as detailed aboveand/or below, wherein: the magnetic force between the magnet apparatusof the implantable component and the magnet apparatus of the externalcomponent, when positioned as would be positioned when used on arecipient at a distance of three mm away from each other, is at least10% greater than that which would be the case with respect to purelyaxial polarity magnets of the same size and same mass and same materialmagnetized at a maximum magnetism while still being usable as a medicalprosthesis. In an exemplary embodiment, there is a medical prosthesis asdetailed above and/or below, wherein: the magnetic force between themagnet apparatus of the implantable component and the magnet apparatusof the external component, when positioned as would be positioned whenused on a recipient at a distance of three mm away from each other, isat least 25% greater than that which would be the case with respect topurely axial polarity magnets of the same size and same mass and samematerial magnetized at a maximum magnetism while still being usable as amedical prosthesis. In an exemplary embodiment, there is a medicalprosthesis as detailed above and/or below, wherein: the magnetic forcebetween the magnet apparatus of the implantable component and the magnetapparatus of the external component, when positioned as would bepositioned when used on a recipient at a distance of 3 mm away from eachother, is at least 100% greater than that which would be the case withrespect to purely diametrical polarity magnets of the same size and samemass and same material magnetized at a maximum magnetism while stillbeing usable as a medical prosthesis. In an exemplary embodiment, thereis a medical prosthesis as detailed above and/or below, wherein: themagnet apparatus of the external component is configured to not rotaterelative to the remainder of the external component. In an exemplaryembodiment, there is a medical prosthesis as detailed above and/orbelow, wherein: the housing and magnet apparatus establish ahousing-magnet apparatus assembly; and the housing-magnet apparatusassembly is configured to resist rotation of the magnet apparatus withinthe housing for magnet fields below 0.5 T. In an exemplary embodiment,there is a medical prosthesis as detailed above and/or below, whereinthe prosthesis is configured such that the magnet apparatus is fixedwithin the prosthesis such that it does not rotate relative to theprosthesis, such as when exposed to one or more or all of the magneticfields detailed herein.

In an exemplary embodiment, there is a method, comprising: subjecting amagnet located in a housing implanted in an implanted medical deviceimplanted in a head of a recipient to a magnetic field of an Millmachine of at least 1.5 T; and maintaining an orientation of the magnetrelative to the housing while the magnet is exposed to the magneticfield, wherein the magnetic field imparts a torque onto the magnet, andwherein the magnet is diametrically magnetized. In an exemplaryembodiment, there is the method described above and/or below wherein:the magnet is part of a magnet group that includes two flanking magnetsthat are axially magnetized. In an exemplary embodiment, there is themethod described above and/or below wherein: the magnet is part of amagnet apparats that includes two flanking components that arenon-magnetic components and are also located in the housing. In anexemplary embodiment, there is the method described above and/or belowwherein: removing the recipient from the magnetic field, wherein afterremoving the recipient from the magnetic field, an orientation of amagnetic field of the magnet has not changed. In an exemplaryembodiment, there is the method described above and/or below wherein:the magnet is part of a magnet apparats that includes two flankingcomponents that are non-magnetic components and are located outside thehousing. In an exemplary embodiment, there is the method described aboveand/or below further comprising reattaching an external medical deviceto the recipient by reestablishing a magnetic connection between theexternal medical device and the magnet of the implanted medical device,wherein the attachment force between the external medical device and theimplant is the same as that which was the case prior to the exposure tothe 1.5 T magnetic field. In an exemplary embodiment, there is themethod described above and/or below wherein: the orientation of theexternal medical device when reattached and subsequently attached iseffectively the same as that which was the case when the externalmedical device was attached to the recipient prior to the action ofremoving the external medical device from the recipient. In an exemplaryembodiment, there is the method described above and/or below wherein:the exposure to the magnetic field takes place at least 6 months afterimplantation of the magnet; and the magnet has effectively never rotatedrelative to the implanted medical device prior the exposure to themagnetic field.

This disclosure described some embodiments of the present technologywith reference to the accompanying drawings, in which only some of thepossible embodiments were shown. Other aspects, however, can be embodiedin many different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments were provided sothat this disclosure was thorough and complete and fully conveyed thescope of the possible embodiments to those skilled in the art.

Any disclosure of a device and/or system detailed herein alsocorresponds to a disclosure of otherwise providing that device and/orsystem and/or utilizing that device and/or system.

It is also noted that any disclosure herein of any process ofmanufacturing other providing a device corresponds to a disclosure of adevice and/or system that results there from. Is also noted that anydisclosure herein of any device and/or system corresponds to adisclosure of a method of producing or otherwise providing or otherwisemaking such. Any disclosure of an embodiment that has a functionallycorresponds to a device configured to have that functionality, and alsocorresponds to a method that results in the functionality/includes theactions associated with the functionality, and vice versa.

Any embodiment or any feature disclosed herein can be combined with anyone or more or other embodiments and/or other features disclosed herein,unless explicitly indicated and/or unless the art does not enable such.Any embodiment or any feature disclosed herein can be explicitlyexcluded from use with any one or more other embodiments and/or otherfeatures disclosed herein, unless explicitly indicated that such iscombined and/or unless the art does not enable such exclusion.

Any function or method action detailed herein corresponds to adisclosure of doing so an automated or semi-automated manner.

Although specific embodiments were described herein, the scope of thetechnology is not limited to those specific embodiments. One skilled inthe art will recognize other embodiments or improvements that are withinthe scope of the present technology. Therefore, the specific structure,acts, or media are disclosed only as illustrative embodiments. The scopeof the technology is defined by the following claims and any equivalentstherein.

Any disclosure herein of any component and/or feature can be combinedwith any one or more of any other component and/or feature disclosureherein unless otherwise noted. Providing that the art enables such. Anydisclosure herein of any component and/or feature can be explicitlyexcluded from combination with any one or more or any other componentand/or feature disclosed herein unless otherwise noted, providing thatthe art enables such. Any disclosure herein of any method actionincludes a disclosure of a device and/or system configured to implementthat method action. Any disclosure herein of a device and/or systemcorresponds to a disclosure of a method of utilizing that device and/orsystem. Any disclosure herein of a manufacturing method corresponds to adisclosure of a device and/or system that results from the manufacturingmethod. Any disclosure of a device and/or system corresponds to adisclosure of a method of making a device and/or system.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not limitation. It will be apparent to persons skilledin the relevant art that various changes in form and detail can be madetherein without departing from the spirit and scope of the invention.

The invention claimed is:
 1. An apparatus comprising: a housing; and amagnet group disposed in the housing, the magnet group generating agroup magnetic field, the magnet group including: a first magnet portionthat produces a first magnetic field; a second magnet portion thatproduces a second magnetic field; and a third magnet portion thatproduces a third magnetic field, wherein the first magnetic field, thesecond magnetic field, and the third magnetic field contribute to thegroup magnetic field, wherein the apparatus is a medical device, thefirst magnet portion is a first end magnet with a magnetizationdirection that extends obliquely to a transcutaneous interface of theapparatus, the second magnet portion is a second end magnet with amagnetization direction extending at an angle to the magnetizationdirection of the first end magnet in an opposite direction, the thirdmagnet portion is an intermediate magnet that is disposed between thefirst and second end magnets, the intermediate magnet having amagnetization direction that is oblique to the magnetization directionof the first and second end magnets, and at least one of: the magnetgroup is configured so that the first magnetization direction and thesecond magnetization direction are fixed relative to each other; or theapparatus is configured so that the magnetization direction of the firstmagnet remains extended towards the transcutaneous interface and themagnetization direction of the second magnet remains extended away fromthe transcutaneous interface.
 2. The apparatus of claim 1, wherein thethird magnet portion is disposed so as to divert a magnetic flux of thefirst magnet portion to the second magnet portion.
 3. The apparatus ofclaim 1, wherein: the apparatus is configured to enable the magnet groupto rotate as a unit relative to the housing about an axial direction. 4.The apparatus of claim 1, wherein: the apparatus is configured such thatthe magnet group resists rotation as a unit relative to the housingabout an axial direction with respect to a first torque range appliedabout the axial direction to the magnet group and enables rotation as aunit relative to the housing about the axial direction with respect to asecond torque range that has components that are larger than thecomponents of the first torque range.
 5. The apparatus of claim 1,wherein: the magnet group is configured such that the first magnetportion, the second magnet portion and the third magnet portionestablish a device such that the first portion and the third portion arecontiguous, and the second portion and the third portion are contiguous;and a cross-section of the magnet group lying on a plane perpendicularto a longitudinal axis of the magnet group contains no gaps ordiscontinuities.
 6. The apparatus of claim 1, wherein: the apparatus isan external component of the medical device; the apparatus is configuredto hold the magnet group fixed as a unit relative to the housing aboutan axial direction when the apparatus is not in magnetic communicationwith an implanted component of the medical device, and configured topermit the magnet group to move as a unit relative to the housing aboutthe axial direction when the apparatus is in magnetic communication withthe implanted component of the medical device.
 7. The apparatus of claim1, wherein: the apparatus is configured such that the magnet group isnon-rotating relative to the housing when the magnet group is free of amagnetic field originating outside the apparatus, but rotating relativeto the housing when the magnet group is exposed to certain magneticfields originating outside the apparatus.
 8. The apparatus of claim 1,wherein the magnet group is located in the housing, and wherein a sideof the magnet group normal to a longitudinal axis of the magnet group isspaced away from the housing by a component located in the housing. 9.The apparatus of claim 1, wherein the magnet group is located in thehousing, and wherein a flat side of the magnet group is spaced away fromthe housing by a bearing body located in the housing.
 10. The apparatusof claim 1, wherein the first magnet portion and second magnet portionare magnetized in respective directions that are obliquely angledrelative to a longitudinal axis of the magnet group.
 11. The apparatusof claim 1, wherein: the apparatus is an external component of a hearingprosthesis.
 12. A system, comprising: the apparatus of claim 8; and asecond apparatus, wherein one of the apparatus or the second apparatusis an external component of the medical device, the other of theapparatus or the second apparatus is an implantable portion of themedical device, and the medical device is a hearing prosthesis.
 13. Theapparatus of claim 8, further comprising: a sound processor.
 14. Theapparatus of claim 8, wherein: the medical device is one of a cochlearimplant, transcutaneous bone conduction device or a direct acousticstimulator.
 15. A system, comprising: the apparatus of claim 1; and asecond apparatus, wherein one of the apparatus or the second apparatusis an external component of the medical device, the other of theapparatus or the second apparatus is an implantable portion of themedical device, and the medical device is a hearing prosthesis.
 16. Theapparatus of claim 1, further comprising: a sound processor.
 17. Theapparatus of claim 1, wherein: the medical device is one of a cochlearimplant, a transcutaneous bone conduction device or a direct acousticstimulator.
 18. A medical prosthesis, comprising: a housing; and amagnet apparatus in the housing, wherein the magnet apparatus isconfigured to provide an axial magnetic flux outside the housing as thestrongest magnetic force relative to a diametrical flux, if present,outside the housing, the housing and magnet apparatus are parts of anexternal component of the medical prosthesis, the medical prosthesisincludes an implantable component that includes a respective magnetapparatus, the medical prosthesis is configured to hold the externalcomponent against skin of the recipient via the axial magnetic flux, andthe magnetic force between the magnet apparatus of the implantablecomponent and the magnet apparatus of the external component, whenpositioned as would be positioned when used on a recipient at a distanceof three mm away from each other, is at least 10% greater than thatwhich would be the case with respect to purely axial polarity magnets ofthe same size and same mass and same material magnetized at a maximummagnetism while still being usable as a medical prosthesis.
 19. Themedical prosthesis of claim 18, wherein: the magnet apparatus has acomponent thereof that produces a diametrically aligned magnetic flux ata geometric center of the magnet apparatus.
 20. The medical prosthesisof claim 18, wherein: the medical device is configured so that themagnet apparatus is rotatable about an axial direction, wherein theaxial direction is at least generally normal to skin of a recipient whenthe medical prosthesis is used with a recipient; and a mechanism islocated inside the housing to sufficiently secure the magnet apparatusso that the magnetic apparatus remains fixed in the absence of magneticfield(s) interacting with the magnet apparatus.
 21. The medicalprosthesis of claim 20, wherein: the medical prosthesis is furtherconfigured so that under the influence of a magnetic field interactingwith the magnet apparatus, the mechanism will allow the magnet apparatusto reorient itself to align with the magnetic field, wherein theorientation will remain until exposed to another magnetic field.
 22. Themedical prosthesis of claim 18, wherein: the magnet apparatus has acomponent thereof that produces a radially aligned magnetic flux awayfrom a geometric center of the magnet apparatus.
 23. The medicalprosthesis of claim 18, wherein: the magnet apparatus has a portionthereof that produces a magnetic flux having an axial component and aradial component away from a geometric center of the magnet apparatus.24. The medical prosthesis of claim 18, wherein: the magnetic forcebetween the magnet apparatus of the implantable component and the magnetapparatus of the external component, when positioned as would bepositioned when used on the recipient at the distance of three mm awayfrom each other, is at least 25% greater than that which would be thecase with respect to purely axial polarity magnets of the same size andsame mass and same material magnetized at the maximum magnetism whilestill being usable as the medical prosthesis.
 25. The medical prosthesisof claim 18, further comprising: a sound processor.
 26. The medicalprosthesis of claim 18, wherein: the medical prosthesis, is one of acochlear implant, a transcutaneous bone conduction device or a directacoustic stimulator.
 27. A method, comprising: during a first timeperiod, subjecting a magnet apparatus including a plurality of magnetportions having respective magnetization directions fixed relative toeach other located in a housing in an implanted component of a medicaldevice implanted in a head of a recipient to a magnetic field, whereinthe implanted component of the medical device is configured to enablethe magnet apparatus to rotate; imparting a torque onto the magnetapparatus via the magnetic field so that the magnet apparatus rotates toa different rotational orientation than before exposure to the magneticfield, during a second time period after the first time period,maintaining the different rotational orientation of the magnet apparatusfor a period of time after the cessation of the exposure to the magneticfield; and during a third time period after the second time period,subjecting the magnet apparatus to a magnetic field of an externalcomponent of the medical device that operates with the implantedcomponent of the medical device as a result of attaching the externalcomponent to the head of the recipient, wherein the exposure of themagnet apparatus of the magnetic field to the external component causesthe magnet apparatus to rotate to another different rotationalorientation from the different rotational orientation.
 28. The method ofclaim 27, wherein: the respective magnetization directions are obliqueto a longitudinal axis of the magnet apparatus.
 29. The method of claim27, wherein: the magnetic field to which the magnet apparatus issubjected during the first time period is from the external component.30. The method of claim 28, wherein: the maintaining of the differentrotational orientation for the period of time is maintained so that atorque of 0.1 inch-pounds onto the magnet apparatus will not rotate themagnet apparatus.
 31. The method of claim 28, wherein: the magneticfield is produced by an MRI machine and is at least 1.5T.
 32. The methodof claim 29, wherein: the attachment of the external component of themedical device to the recipient reestablishes a magnetic connectionbetween the external component of the medical device and the magnet ofthe implanted component of the medical device, wherein the attachmentforce between the external medical device and the implanted component ofthe medical device is the same as that which was the case prior to theexposure to the 1.5T magnetic field.
 33. A medical prosthesis,comprising: a housing; and a magnet apparatus in the housing, whereinthe magnet apparatus is configured to provide an axial magnetic fluxoutside the housing as the strongest magnetic force relative to adiametrical flux, if present, outside the housing, the medical device isconfigured so that the magnet apparatus is rotatable about an axialdirection, wherein the axial direction is at least generally normal toskin of a recipient when the medical prosthesis is used with therecipient, and a feature inside the housing results in a reduction ofthe total amount of rotation that would be experienced with respect toexposure to a given magnetic field by at least 90% relative to thatwhich would exist without the utilization of the feature for thatmagnetic field.
 34. The apparatus of claim 33, wherein the feature is anangled polar alignment.
 35. The apparatus of claim 33, wherein thefeature is a flanking magnetic portion flanking a central magneticportion, the flanking magnetic portion having an angled polar alignment.36. An apparatus comprising: a housing; and a magnet group disposed inthe housing, the magnet group generating a group magnetic field, themagnet group including: a first magnet portion that produces a firstmagnetic field; a second magnet portion that produces a second magneticfield; and a third magnet portion that produces a third magnetic field,wherein the first magnetic field, the second magnetic field, and thethird magnetic field contribute to the group magnetic field, wherein theapparatus is a medical device, the third magnet portion is diametricallymagnetized, and wherein the first magnet portion and second magnetportion are magnetized in respective directions that are obliquelyangled relative to the magnetization direction of the third magnetportion, and the first, second and third magnet portions are the onlymagnet portions located in the housing, and the third magnet portion isin between the first magnet portion and the second magnet portion. 37.The apparatus of claim 36, wherein: the magnet group is a disk-likemagnet group.
 38. The apparatus of claim 36, wherein: the magnet groupis a disk having a circular outer profile.
 39. The device of claim 36,wherein: the first magnetization direction is different from an axis ofrotational symmetry of the magnet group.
 40. The device of claim 36,wherein: the magnetization direction of the first magnet portion isangled at a first non-zero angle from a longitudinal axis of the magnetgroup and the magnetization direction of the second magnet portion isangled at a second non-zero-angle from the longitudinal axis; and thevalue of the first non-zero angle is the same as the value of the secondnon-zero angle.
 41. The device of claim 36, wherein: the direction ofmagnetization of the third magnet portion is normal to a longitudinalaxis of the magnet group.
 42. An apparatus comprising: a housing; and amagnet group disposed in the housing, the magnet group generating agroup magnetic field, the magnet group including: a first magnet portionthat produces a first magnetic field; a second magnet portion thatproduces a second magnetic field; and a third magnet portion thatproduces a third magnetic field, wherein the first magnetic field, thesecond magnetic field, and the third magnetic field contribute to thegroup magnetic field, wherein the apparatus is a medical device, and thefirst magnet portion and second magnet portion are magnetized inrespective directions that are between 20 degrees and 70 degrees from alongitudinal axis of the magnet group, the respective directions beingfixed relative to each other, the first, second and third magnetportions making up all of the magnet portions in the housing.
 43. Theapparatus of claim 42, wherein: the first magnet portion is a first endmagnet with a magnetization direction that extends obliquely to atranscutaneous interface of the apparatus; the second magnet portion isa second end magnet with a magnetization direction extending at an angleto the magnetization direction of the first end magnet in an oppositedirection; and the third magnet portion is an intermediate magnet thatis disposed between the first and second end magnets, the intermediatemagnet having a magnetization direction that is oblique to themagnetization direction of the first and second end magnets.
 44. Themedical prosthesis of claim 42, wherein: the housing and magnetapparatus are parts of an external component of the medical prosthesis;the medical prosthesis includes an implantable component that includes arespective magnet apparatus; and the medical prosthesis is configured tohold the external component against skin of the recipient via the axialmagnetic flux.
 45. The medical prosthesis of claim 44, wherein: themagnetic force between the magnet apparatus of the implantable componentand the magnet apparatus of the external component, when positioned aswould be positioned when used on a recipient at a distance of three mmaway from each other, is at least 10% greater than that which would bethe case with respect to purely axial polarity magnets of the same sizeand same mass and same material magnetized at a maximum magnetism whilestill being usable as a medical prosthesis.
 46. The device of claim 42,wherein: the direction of magnetization of the third magnet portion isnormal to the longitudinal axis.
 47. The apparatus of claim 42, wherein:the magnet group is a disk-like magnet group.
 48. The apparatus of claim42, wherein: the magnet group is a disk having a circular outer profile.49. The apparatus of claim 42, wherein: the third magnet portion islocated between the first magnet portion and the second magnet portion.50. The apparatus of claim 42, wherein: the third magnet portion isdisposed so as to divert the first magnetic field to the second magnetportion.